Among 10 companions including Abu Qatadah, Humaid As-Sa'idi details how Rasulullah performed Salah. Noteably, he explicitly recounts Rasulullah (ﷺ) observing Sadl, stating, "ensure every part of his body would settle in its place."

Reference: Sunan Ibn Majah 1061

Sunan Ibn Majah 1061
Muhammad bin ‘Amr bin ‘Ata’ said:

‘While he was among ten of the Companions of the Messenger of Allah (ﷺ) including Abu Qatadah: “I heard Abu Humaid As-Sa’idi say: ‘I am the most knowledgeable of you concerning the prayer of the Messenger of Allah (ﷺ).’ They said: ‘Why? By Allah, you did not follow him more than we did, and you did not accompany him for longer.’ He said: ‘Yes I am.’ They said: ‘Show us.’ He said: ‘When the Messenger of Allah (ﷺ) stood up for prayer, he would say the Takbir, then he would raise his hands parallel to his shoulders, and then ensure every part of his body would settle in its place, and then he would recite. Then he would say the Takbir and raise his hands parallel to his shoulders and bow, placing his palms on his knees and supporting his weight on them. He neither lowered his head, nor raised it up, it was evenly balanced (between either extreme). Then he would say: “Sami’ Allahu liman hamidah (Allah hears those who praise Him); and he would raise his hands parallel with his shoulders, until every bone returned to its place. Then he would prostrate himself on the ground, keeping his arms away from his sides. Then he would raise his head and tuck his left foot under him and sit on it, and he would spread his toes when he prostrated.* Then he would prostrate, then say the Takbir and sit on his left foot, until every bone returned to its place. Then he would stand up and do the same in the next Rak’ah. Then when he stood up after two Rak’ah, he would raise his hands level with his shoulders as he did at the beginning of the prayer. Then he would offer the rest of his prayer in like manner until, when he did the prostration after which the Taslim comes, he would push one of his feet back and sit with his weight on his left side, Mutawarrikan.’** They said: ‘You have spoken the truth; this is how the Messenger of Allah (ﷺ) used to perform the prayer.’”

حَدَّثَنَا مُحَمَّدُ بْنُ بَشَّارٍ، حَدَّثَنَا أَبُو عَاصِمٍ، حَدَّثَنَا عَبْدُ الْحَمِيدِ بْنُ جَعْفَرٍ، حَدَّثَنَا مُحَمَّدُ بْنُ عَمْرِو بْنِ عَطَاءٍ، قَالَ سَمِعْتُ أَبَا حُمَيْدٍ السَّاعِدِيَّ، فِي عَشْرَةٍ مِنْ أَصْحَابِ رَسُولِ اللَّهِ ـ صلى الله عليه وسلم ـ فِيهِمْ أَبُو قَتَادَةَ فَقَالَ أَبُو حُمَيْدٍ أَنَا أَعْلَمُكُمْ بِصَلاَةِ رَسُولِ اللَّهِ ـ صلى الله عليه وسلم ـ ‏.‏ قَالُوا لِمَ فَوَاللَّهِ مَا كُنْتَ بِأَكْثَرِنَا لَهُ تَبَعَةً وَلاَ أَقْدَمَنَا لَهُ صُحْبَةً ‏.‏ قَالَ بَلَى ‏.‏ قَالُوا فَاعْرِضْ ‏.‏ قَالَ كَانَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ إِذَا قَامَ إِلَى الصَّلاَةِ كَبَّرَ ثُمَّ رَفَعَ يَدَيْهِ حَتَّى يُحَاذِيَ بِهِمَا مَنْكِبَيْهِ وَيَقِرَّ كُلُّ عُضْوٍ مِنْهُ فِي مَوْضِعِهِ ثُمَّ يَقْرَأُ ثُمَّ يُكَبِّرُ وَيَرْفَعُ يَدَيْهِ حَتَّى يُحَاذِيَ بِهِمَا مَنْكِبَيْهِ ثُمَّ يَرْكَعُ وَيَضَعُ رَاحَتَيْهِ عَلَى رُكْبَتَيْهِ مُعْتَمِدًا لاَ يَصُبُّ رَأْسَهُ وَلاَ يُقْنِعُ مُعْتَدِلاً ثُمَّ يَقُولُ ‏ "‏ سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ ‏"‏ ‏.‏ وَيَرْفَعُ يَدَيْهِ حَتَّى يُحَاذِيَ بِهِمَا مَنْكِبَيْهِ حَتَّى يَقِرَّ كُلُّ عَظْمٍ إِلَى مَوْضِعِهِ ثُمَّ يَهْوِي إِلَى الأَرْضِ وَيُجَافِي يَدَيْهِ عَنْ جَنْبَيْهِ ثُمَّ يَرْفَعُ رَأْسَهُ وَيَثْنِي رِجْلَهُ الْيُسْرَى فَيَقْعُدُ عَلَيْهَا وَيَفْتَخُ أَصَابِعَ رِجْلَيْهِ إِذَا سَجَدَ ثُمَّ يَسْجُدُ ثُمَّ يُكَبِّرُ وَيَجْلِسُ عَلَى رِجْلِهِ الْيُسْرَى حَتَّى يَرْجِعَ كُلُّ عَظْمٍ مِنْهُ إِلَى مَوْضِعِهِ ثُمَّ يَقُومُ فَيَصْنَعُ فِي الرَّكْعَةِ الأُخْرَى مِثْلَ ذَلِكَ ثُمَّ إِذَا قَامَ مِنَ الرَّكْعَتَيْنِ رَفَعَ يَدَيْهِ حَتَّى يُحَاذِيَ بِهِمَا مَنْكِبَيْهِ كَمَا صَنَعَ عِنْدَ افْتِتَاحِ الصَّلاَةِ ثُمَّ يُصَلِّي بَقِيَّةَ صَلاَتِهِ هَكَذَا حَتَّى إِذَا كَانَتِ السَّجْدَةُ الَّتِي يَنْقَضِي فِيهَا التَّسْلِيمُ أَخَّرَ إِحْدَى رِجْلَيْهِ وَجَلَسَ عَلَى شِقِّهِ الأَيْسَرِ مُتَوَرِّكًا ‏.‏ قَالُوا صَدَقْتَ هَكَذَا كَانَ يُصَلِّي رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ ‏.‏
Reference  : Sunan Ibn Majah 1061
In-book reference  : Book 5, Hadith 259
 
On a separate occassion, Sahl makes clear, Rasulullah (ﷺ) "stood straight until every bone had returned to its place."

Reference: Sunan Ibn Majah 863

Sunan Ibn Majah 863
'Abbas bin Sahl As-Sa'di said:

“Abu Humaid, Abu Usaid As-Sa’di, Sahl bin Sa’d, and Muhammad bin Maslamah came together and spoke about the prayer of the Messenger of Allah (ﷺ). Abu Humaid said: ‘I am the most knowledgeable of you about the prayer of the Messenger of Allah (ﷺ). The Messenger of Allah (ﷺ) stood up and said Allahu Akbar, and raised his hands, then he raised them when he said Allahu Akbar for Ruku’, then he stood up and raised his hands, and stood straight until every bone had returned to its place.’”

حَدَّثَنَا مُحَمَّدُ بْنُ بَشَّارٍ، حَدَّثَنَا أَبُو عَامِرٍ، حَدَّثَنَا فُلَيْحُ بْنُ سُلَيْمَانَ، حَدَّثَنَا عَبَّاسُ بْنُ سَهْلٍ السَّاعِدِيُّ، قَالَ اجْتَمَعَ أَبُو حُمَيْدٍ وَأَبُو أُسَيْدٍ السَّاعِدِيُّ وَسَهْلُ بْنُ سَعْدٍ وَمُحَمَّدُ بْنُ مَسْلَمَةَ فَذَكَرُوا صَلاَةَ رَسُولِ اللَّهِ ـ صلى الله عليه وسلم ـ فَقَالَ أَبُو حُمَيْدٍ أَنَا أَعْلَمُكُمْ بِصَلاَةِ رَسُولِ اللَّهِ ـ صلى الله عليه وسلم ـ إِنَّ رَسُولَ اللَّهِ ـ صلى الله عليه وسلم ـ قَامَ فَكَبَّرَ وَرَفَعَ يَدَيْهِ، ثُمَّ رَفَعَ حِينَ كَبَّرَ لِلرُّكُوعِ، ثُمَّ قَامَ فَرَفَعَ يَدَيْهِ، وَاسْتَوَى حَتَّى رَجَعَ كُلُّ عَظْمٍ إِلَى مَوْضِعِهِ ‏.
Reference  : Sunan Ibn Majah 863
In-book reference  : Book 5, Hadith 61
 
In a different, widely reported, narration, Rasulullah (ﷺ) did not instruct the observance of Qabd (folding of the arms)

Reference: Sahih al-Bukhari 6667

Sahih al-Bukhari 6667
Narrated Abu Huraira:

A man entered the mosque and started praying while Allah's Messenger (ﷺ) was sitting somewhere in the mosque. Then (after finishing the prayer) the man came to the Prophet (ﷺ) and greeted him. The Prophet (ﷺ) said to him, "Go back and pray, for you have not prayed. The man went back, and having prayed, he came and greeted the Prophet. The Prophet (ﷺ) after returning his greetings said, "Go back and pray, for you did not pray." On the third time the man said, "(O Allah's Messenger (ﷺ)!) teach me (how to pray)." The Prophet said, "When you get up for the prayer, perform the ablution properly and then face the Qibla and say Takbir (Allahu Akbar), and then recite of what you know of the Qur'an, and then bow, and remain in this state till you feel at rest in bowing, and then raise your head and stand straight; and then prostrate till you feel at rest in prostration, and then sit up till you feel at rest while sitting; and then prostrate again till you feel at rest in prostration; and then get up and stand straight, and do all this in all your prayers."

حَدَّثَنِي إِسْحَاقُ بْنُ مَنْصُورٍ، حَدَّثَنَا أَبُو أُسَامَةَ، حَدَّثَنَا عُبَيْدُ اللَّهِ بْنُ عُمَرَ، عَنْ سَعِيدِ بْنِ أَبِي سَعِيدٍ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَجُلاً، دَخَلَ الْمَسْجِدَ يُصَلِّي وَرَسُولُ اللَّهِ صلى الله عليه وسلم فِي نَاحِيَةِ الْمَسْجِدِ، فَجَاءَ فَسَلَّمَ عَلَيْهِ فَقَالَ لَهُ ‏"‏ ارْجِعْ فَصَلِّ، فَإِنَّكَ لَمْ تُصَلِّ ‏"‏‏.‏ فَرَجَعَ فَصَلَّى، ثُمَّ سَلَّمَ فَقَالَ ‏"‏ وَعَلَيْكَ، ارْجِعْ فَصَلِّ، فَإِنَّكَ لَمْ تُصَلِّ ‏"‏‏.‏ قَالَ فِي الثَّالِثَةِ فَأَعْلِمْنِي‏.‏ قَالَ ‏"‏ إِذَا قُمْتَ إِلَى الصَّلاَةِ فَأَسْبِغِ الْوُضُوءَ، ثُمَّ اسْتَقْبِلِ الْقِبْلَةَ فَكَبِّرْ، وَاقْرَأْ بِمَا تَيَسَّرَ مَعَكَ مِنَ الْقُرْآنِ، ثُمَّ ارْكَعْ حَتَّى تَطْمَئِنَّ رَاكِعًا، ثُمَّ ارْفَعْ رَأْسَكَ حَتَّى تَعْتَدِلَ قَائِمًا، ثُمَّ اسْجُدْ حَتَّى تَطْمَئِنَّ، سَاجِدًا ثُمَّ ارْفَعْ حَتَّى تَسْتَوِيَ وَتَطْمَئِنَّ جَالِسًا، ثُمَّ اسْجُدْ حَتَّى تَطْمَئِنَّ سَاجِدًا، ثُمَّ ارْفَعْ حَتَّى تَسْتَوِيَ قَائِمًا، ثُمَّ افْعَلْ ذَلِكَ فِي صَلاَتِكَ كُلِّهَا ‏"‏‏.‏
Reference  : Sahih al-Bukhari 6667
In-book reference  : Book 83, Hadith 45
 
In an elaborate version of this hadith, narrated by a companion who took part in Badr, Qabd (clasping of the hands) is still not prescribed.

Reference: Sunan an-Nasa'i 1136

Sunan an-Nasa'i 1136
It was narrated that Rifa'ah bin Rafi' said:

"While the Messenger of Allah (ﷺ) was sitting with us around him, a man came in, turned towards the Qiblah and prayed. When he had finished his prayer, he came and greeted the Messenger of Allah (ﷺ) and the people with Salam. The Messenger of Allah (ﷺ) said to him: 'And also to you. Go and pray, for you have not prayed.' So he went and prayed, and the Messenger of Allah (ﷺ) started watching him, and he (the man) did not know what was wrong with it. When he had finished the prayer, he came and greeted the Messenger of Allah (ﷺ) and the people with salam. The Messenger of Allah (ﷺ) said to him: 'And also to you. Go and pray, for you have not prayed.' He repeated it two or three times, then the man said: 'O Messenger of Allah, what is wrong with my prayer?' The Messenger of Allah (ﷺ) said: 'The prayer of any of you is not complete unless he performs wudu properly as enjoined by Allah, the Mighty and Sublime. So he should wash his face, his arms up to the elbows, and wipe his head, and his feet up to the ankles. Then he should magnify Allah (SWT) and praise Him and glorify Him.'" - (One of the narrators) Hammam said: "I heard him say: 'He should praise Allah and glorify Him and magnify Him." He said: "I heard both of them." - "He (the Prophet (ﷺ)) said: 'He should recite whatever is easy for him of the Quran that Allah has taught him and permitted him in it (the prayer). Then he should say the Takbir and bow until his joints settle and he is relaxed. Then he should say: 'Sami Allahu liman hamidah (Allah hears the one who praises Him)' and stand up straight until his backbone is straight (and at ease). Then he should say Takbir and prostrate until he has placed his face firmly on the ground." "I heard him say: his forehead, until his joints settle and he is relaxed. Then he should say the Takbir and sit up until his backbone is straight (and at ease). Then he should prostrate until he has placed his face firmly on the ground and he is relaxed. If he does not do that then he has not completed his prayer."

أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ يَزِيدَ الْمُقْرِئُ أَبُو يَحْيَى، بِمَكَّةَ - وَهُوَ بَصْرِيٌّ - قَالَ حَدَّثَنَا أَبِي قَالَ، حَدَّثَنَا هَمَّامٌ، قَالَ حَدَّثَنَا إِسْحَاقُ بْنُ عَبْدِ اللَّهِ بْنِ أَبِي طَلْحَةَ، أَنَّ عَلِيَّ بْنَ يَحْيَى بْنِ خَلاَّدِ بْنِ مَالِكِ بْنِ رَافِعِ بْنِ مَالِكٍ، حَدَّثَهُ عَنْ أَبِيهِ، عَنْ عَمِّهِ، رِفَاعَةَ بْنِ رَافِعٍ قَالَ بَيْنَمَا رَسُولُ اللَّهِ صلى الله عليه وسلم جَالِسٌ وَنَحْنُ حَوْلَهُ إِذْ دَخَلَ رَجُلٌ فَأَتَى الْقِبْلَةَ فَصَلَّى فَلَمَّا قَضَى صَلاَتَهُ جَاءَ فَسَلَّمَ عَلَى رَسُولِ اللَّهِ صلى الله عليه وسلم وَعَلَى الْقَوْمِ فَقَالَ لَهُ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ وَعَلَيْكَ اذْهَبْ فَصَلِّ فَإِنَّكَ لَمْ تُصَلِّ ‏"‏ ‏.‏ فَذَهَبَ فَصَلَّى فَجَعَلَ رَسُولُ اللَّهِ صلى الله عليه وسلم يَرْمُقُ صَلاَتَهُ وَلاَ يَدْرِي مَا يَعِيبُ مِنْهَا فَلَمَّا قَضَى صَلاَتَهُ جَاءَ فَسَلَّمَ عَلَى رَسُولِ اللَّهِ صلى الله عليه وسلم وَعَلَى الْقَوْمِ فَقَالَ لَهُ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ وَعَلَيْكَ اذْهَبْ فَصَلِّ فَإِنَّكَ لَمْ تُصَلِّ ‏"‏ ‏.‏ فَأَعَادَهَا مَرَّتَيْنِ أَوْ ثَلاَثًا فَقَالَ الرَّجُلُ يَا رَسُولَ اللَّهِ مَا عِبْتَ مِنْ صَلاَتِي فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ إِنَّهَا لَمْ تَتِمَّ صَلاَةُ أَحَدِكُمْ حَتَّى يُسْبِغَ الْوُضُوءَ كَمَا أَمَرَهُ اللَّهُ عَزَّ وَجَلَّ فَيَغْسِلَ وَجْهَهُ وَيَدَيْهِ إِلَى الْمِرْفَقَيْنِ وَيَمْسَحَ بِرَأْسِهِ وَرِجْلَيْهِ إِلَى الْكَعْبَيْنِ ثُمَّ يُكَبِّرَ اللَّهَ عَزَّ وَجَلَّ وَيَحْمَدَهُ وَيُمَجِّدَهُ ‏"‏ ‏.‏ قَالَ هَمَّامٌ وَسَمِعْتُهُ يَقُولُ ‏"‏ وَيَحْمَدَ اللَّهَ وَيُمَجِّدَهُ وَيُكَبِّرَهُ ‏"‏ ‏.‏ قَالَ فَكِلاَهُمَا قَدْ سَمِعْتُهُ يَقُولُ قَالَ ‏"‏ وَيَقْرَأَ مَا تَيَسَّرَ مِنَ الْقُرْآنِ مِمَّا عَلَّمَهُ اللَّهُ وَأَذِنَ لَهُ فِيهِ ثُمَّ يُكَبِّرَ وَيَرْكَعَ حَتَّى تَطْمَئِنَّ مَفَاصِلُهُ وَتَسْتَرْخِيَ ثُمَّ يَقُولَ سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ ثُمَّ يَسْتَوِيَ قَائِمًا حَتَّى يُقِيمَ صُلْبَهُ ثُمَّ يُكَبِّرَ وَيَسْجُدَ حَتَّى يُمَكِّنَ وَجْهَهُ ‏"‏ ‏.‏ وَقَدْ سَمِعْتُهُ يَقُولُ ‏"‏ جَبْهَتَهُ حَتَّى تَطْمَئِنَّ مَفَاصِلُهُ وَتَسْتَرْخِيَ وَيُكَبِّرَ فَيَرْفَعَ حَتَّى يَسْتَوِيَ قَاعِدًا عَلَى مَقْعَدَتِهِ وَيُقِيمَ صُلْبَهُ ثُمَّ يُكَبِّرَ فَيَسْجُدَ حَتَّى يُمَكِّنَ وَجْهَهُ وَيَسْتَرْخِيَ فَإِذَا لَمْ يَفْعَلْ هَكَذَا لَمْ تَتِمَّ صَلاَتُهُ ‏"‏ ‏.‏
Reference  : Sunan an-Nasa'i 1136
In-book reference  : Book 12, Hadith 108
 
Qabd (folding or clasping of the hands) is also not prescribed when narrating the Sunnah of Salah.

Reference: Sunan an-Nasa'i 1280

Sunan an-Nasa'i 1280
It was narrated from Hittan bin 'Abdullah that Al-Ash'ari said:

"The Messenger of Allah (ﷺ) addressed us and taught us our Sunnahs and our prayer. He said: 'When you stand for the prayer, make your rows straight, then let one of you lead the others. When he says the takbir, then say the takbir; when he says : "Wa lad-dallin" then say "Amin" and Allah (SWT) will answer you. Then when he says the takbir and bows, then say the takbir and bow, for the Imam bows before you and stands up before you.' The Prophet of Allah (ﷺ) said: "This makes up for that. When he says: 'Sami' Allahu liman hamidah (Allah hears the one who praises Him),' say: 'Allahumma, Rabbana wa lakal-hamd (O Allah, our Lord, to You be praise),' Allah will hear you, for indeed Allah (SWT), the Mighty and Sublime, has said on the tongue of His Prophet: "Allah hears the one who praises Him." Then when he says the takbir and prostrates, say the takbir and prostrate, for the Imam prostrates before you and rises before you.' The Prophet of Allah (ﷺ) said: 'This makes up for that. Then when you are sitting, let the following be among what one of you says: At-tahiyyatu lillahi wasalawatu wat-tayibaat, as-salamu 'alaika ayah-Nabiyyu wa rahmatAllahi wa baraktuhu. As-salamu 'alaina a 'ala ibad illahis-salihin, ashadu an la ilaha ill Allah, wa ashhadu anna Muhammadan 'abduhu wa rasuluhu. (All compliments, prayers and pure words are due to Allah. Peace be upon you O Prophet, and the mercy of Allah and His blessings. Peace be upon us and upon the righteous slaves of Allah. I bear witness that that none has the right to be worshipped except Allah, and I bear witness that Muhammad is His slave and messenger.)"

أَخْبَرَنَا مُحَمَّدُ بْنُ بَشَّارٍ، قَالَ حَدَّثَنَا يَحْيَى بْنُ سَعِيدٍ، عَنْ هِشَامٍ، عَنْ قَتَادَةَ، ح وَأَنْبَأَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، قَالَ حَدَّثَنَا يَحْيَى، قَالَ حَدَّثَنَا هِشَامٌ، قَالَ حَدَّثَنَا قَتَادَةُ، عَنْ يُونُسَ بْنِ جُبَيْرٍ، عَنْ حِطَّانَ بْنِ عَبْدِ اللَّهِ، أَنَّ الأَشْعَرِيَّ، قَالَ إِنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم خَطَبَنَا فَعَلَّمَنَا سُنَّتَنَا وَبَيَّنَ لَنَا صَلاَتَنَا فَقَالَ ‏"‏ إِذَا قُمْتُمْ إِلَى الصَّلاَةِ فَأَقِيمُوا صُفُوفَكُمْ ثُمَّ لْيَؤُمَّكُمْ أَحَدُكُمْ فَإِذَا كَبَّرَ فَكَبِّرُوا وَإِذَا قَالَ ‏{‏ وَلاَ الضَّالِّينَ ‏}‏ فَقُولُوا آمِينَ يُجِبْكُمُ اللَّهُ ثُمَّ إِذَا كَبَّرَ وَرَكَعَ فَكَبِّرُوا وَارْكَعُوا فَإِنَّ الإِمَامَ يَرْكَعُ قَبْلَكُمْ وَيَرْفَعُ قَبْلَكُمْ ‏"‏ ‏.‏ قَالَ نَبِيُّ اللَّهِ صلى الله عليه وسلم ‏"‏ فَتِلْكَ بِتِلْكَ وَإِذَا قَالَ سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ فَقُولُوا اللَّهُمَّ رَبَّنَا لَكَ الْحَمْدُ فَإِنَّ اللَّهَ عَزَّ وَجَلَّ قَالَ عَلَى لِسَانِ نَبِيِّهِ صلى الله عليه وسلم سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ ثُمَّ إِذَا كَبَّرَ وَسَجَدَ فَكَبِّرُوا وَاسْجُدُوا فَإِنَّ الإِمَامَ يَسْجُدُ قَبْلَكُمْ وَيَرْفَعُ قَبْلَكُمْ ‏"‏ ‏.‏ قَالَ نَبِيُّ اللَّهِ صلى الله عليه وسلم ‏"‏ فَتِلْكَ بِتِلْكَ وَإِذَا كَانَ عِنْدَ الْقَعْدَةِ فَلْيَكُنْ مِنْ قَوْلِ أَحَدِكُمْ أَنْ يَقُولَ التَّحِيَّاتُ الطَّيِّبَاتُ الصَّلَوَاتُ لِلَّهِ السَّلاَمُ عَلَيْكَ أَيُّهَا النَّبِيُّ وَرَحْمَةُ اللَّهِ وَبَرَكَاتُهُ السَّلاَمُ عَلَيْنَا وَعَلَى عِبَادِ اللَّهِ الصَّالِحِينَ أَشْهَدُ أَنْ لاَ إِلَهَ إِلاَّ اللَّهُ وَأَشْهَدُ أَنَّ مُحَمَّدًا عَبْدُهُ وَرَسُولُهُ ‏"‏ ‏.‏
Reference  : Sunan an-Nasa'i 1280
In-book reference  : Book 13, Hadith 102
 
The only reference to Qabd in Sahih al-Bukhari is Hadith 740. The hadith suggests Qabd was performed under duress. It's attribution to Rasulullah (ﷺ) appears to be very unreliable given that a chain of narrators is not provided.

Reference: Sahih al-Bukhari 740

Sahih al-Bukhari 740
Narrated Sahl bin Sa`d:

The people were ordered to place the right hand on the left forearm in the prayer. Abu Hazim said, "I only know that it is attributed to the Prophet (ﷺ) ." Ismael said "it's attributed that way." But he didn't say how it's attributed.

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ، عَنْ مَالِكٍ، عَنْ أَبِي حَازِمٍ، عَنْ سَهْلِ بْنِ سَعْدٍ، قَالَ كَانَ النَّاسُ يُؤْمَرُونَ أَنْ يَضَعَ الرَّجُلُ الْيَدَ الْيُمْنَى عَلَى ذِرَاعِهِ الْيُسْرَى فِي الصَّلاَةِ‏.‏ قَالَ أَبُو حَازِمٍ لاَ أَعْلَمُهُ إِلاَّ يَنْمِي ذَلِكَ إِلَى النَّبِيِّ صلى الله عليه وسلم‏.‏ قَالَ إِسْمَاعِيلُ يُنْمَى ذَلِكَ‏.‏ وَلَمْ يَقُلْ يَنْمِي‏.‏
Reference  : Sahih al-Bukhari 740
In-book reference  : Book 10, Hadith 134

Note: The Arabic of this Hadith has been retranslated for concern of significant inaccuracies in the popular English translation. Neither Abu Hazim nor Ismael vouch for the veracity of the attribution, nor provide a verifiable chain of narrators, nor claim to follow the practise. They claim "it has been attributed," but do not attribute it themselves in the personal pronoun.

 
The major reference from Sahih Muslim is attributed to one person, yet narrated by another.

Reference: Sahih Muslim 401

Sahih Muslim 401
Wa'il b. Hujr reported:

He saw the Messenger of Allah (ﷺ) raising his hands at the time of beginning the prayer and reciting takbir, and according to Hammam (the narrator), the hands were lifted opposite to ears. He (the Holy Prophet) then wrapped his hands in his cloth and placed his right hand over his left hand. And when he was about to bow down, he brought out his hands from the cloth, and then lifted them, and then recited takbir and bowed down, and when (he came back to the erect position) he recited:" Allah listened to him who praised Him." And when he prostrated, he prostrated between his two palms.

حَدَّثَنَا زُهَيْرُ بْنُ حَرْبٍ، حَدَّثَنَا عَفَّانُ، حَدَّثَنَا هَمَّامٌ، حَدَّثَنَا مُحَمَّدُ بْنُ جُحَادَةَ، حَدَّثَنِي عَبْدُ الْجَبَّارِ بْنُ وَائِلٍ، عَنْ عَلْقَمَةَ بْنِ وَائِلٍ، وَمَوْلًى، لَهُمْ أَنَّهُمَا حَدَّثَاهُ عَنْ أَبِيهِ، وَائِلِ بْنِ حُجْرٍ، أَنَّهُ رَأَى النَّبِيَّ صلى الله عليه وسلم رَفَعَ يَدَيْهِ حِينَ دَخَلَ فِي الصَّلاَةِ كَبَّرَ - وَصَفَ هَمَّامٌ حِيَالَ أُذُنَيْهِ - ثُمَّ الْتَحَفَ بِثَوْبِهِ ثُمَّ وَضَعَ يَدَهُ الْيُمْنَى عَلَى الْيُسْرَى فَلَمَّا أَرَادَ أَنْ يَرْكَعَ أَخْرَجَ يَدَيْهِ مِنَ الثَّوْبِ ثُمَّ رَفَعَهُمَا ثُمَّ كَبَّرَ فَرَكَعَ فَلَمَّا قَالَ ‏ "‏ سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ ‏"‏ ‏.‏ رَفَعَ يَدَيْهِ فَلَمَّا سَجَدَ سَجَدَ بَيْنَ كَفَّيْهِ ‏.‏
Reference  : Sahih Muslim 401
In-book reference  : Book 4, Hadith 58

Note: In the middle of this Hadith, the narrator changes to Hammam who is then narrating the practises of the Prophet. Yet, Hammam never met the Prophet. If the second part of the Hadith could be traced back to Wa'il b. Hujr, stating "Description of Hammam" would be inappropriate as Hammam is a listed narrator of the first part of the Hadith, and he is narrating the description of Wa'il b. Hujr, not his own. This suggests that the narration of Qabd is not traced back to Rasulullah (ﷺ) but rather to Hammam. There are no corroborating references for this Hadith in other books of Sahih.