"I was the most attentive among you in memorizing the prayer of the Messenger of Allah ﷺ. I saw that when he said the opening takbir, he raised his hands level with his shoulders. When he bowed, he placed his hands firmly on his knees, then he straightened his back. When he raised his head from bowing, he stood upright until every vertebra returned to its place. When he prostrated, he placed his hands on the ground neither spread out flat nor clenched, and he pointed the tips of his toes toward the qiblah. When he sat after the first two rak'ahs, he sat on his left foot with the right foot upright. When he sat in the final rak'ah, he placed his left foot forward, kept the right one upright, and sat on his buttocks."
أنا كنت احفظكم لصلاة رسول الله ﷺ، رأيته إذا كبر جعل يديه حذاء منكبيه، وإذا ركع أمكن يديه من ركبتيه، ثم هصر ظهره، فإذا رفع رأسه استوى حتى يعود كل فقار مكانه، فإذا سجد وضع يديه غير مفترش ولا قابضهما، واستقبل بأطراف أصابع رجليه القبلة، فإذا جلس في الركعتين جلس على رجله اليسرى، ونصب اليمنى، وإذا جلس في الركعة الآخرة قدم رجله اليسرى ونصب الأخرى، وقعد على مقعدته.
Bukhari narrated it in Adhan (828), he said, Yahya bin Bukayr told us, he said, Layth told us, from Khalid (he is Ibn Yazid Jumahi Misri), from Saeed (Ibn Abu Hilal), from Muhammad bin Amr bin Halhala, from Muhammad bin Amr bin Ata, and Layth also told us from Yazid bin Abu Habib and Yazid bin Muhammad, from Muhammad bin Amr bin Halhala, from Muhammad bin Amr bin Ata, that he was sitting with a group of the companions of the Prophet ﷺ, and we mentioned the prayer of the Prophet ﷺ, so Abu Humayd Saadi mentioned the hadith, in this abridged form.Abu Dawud (730), Tirmidhi (304), and Ibn Majah (1061) all narrated it through the route of Abdul-Hameed bin Jafar, who said, Muhammad bin Amr bin Ata told me, he said, I heard Abu Humayd Saadi, among ten of the companions of the Messenger of Allah ﷺ, including Abu Qatada, say, Abu Humayd said, I am the most knowledgeable among you about the prayer of the Messenger of Allah ﷺ. They said, Why is that? By Allah, you were not the one who followed him most, nor the earliest of us in companionship with him. He said, Yes I am. They said, Then show us. He said, When the Messenger of Allah ﷺ stood up for prayer, he would raise his hands until they were level with his shoulders, then say the takbir until every bone settled evenly in its place, then he would recite. Then he would say the takbir, raising his hands until they were level with his shoulders, then bow in ruku, placing his palms on his knees, then he would settle evenly, neither dropping his head nor raising it up. Then he would raise his head and say, "Allah hears whoever praises Him," then he would raise his hands until they were level with his shoulders, settled evenly, then he would say, "Allah is greatest," then he would descend toward the ground, keeping his hands away from his sides. Then he would raise his head and fold his left leg, sitting upon it, and he would spread the toes of his feet when he prostrated. He would perform the sajdah, then say, "Allah is greatest," and raise his head, folding his left leg and sitting upon it, until every bone returned to its place. Then he would do the same in the second sajdah. When he rose from the two rakats, he would say the takbir and raise his hands until they were level with his shoulders, just as he had done the takbir when opening the prayer. Then he would continue doing this throughout the rest of his prayer, until when it came to the sajdah that contained the tasleem, he would draw back his left leg and sit tawarruk on his left side.They said, You have spoken truly. This is how he ﷺ used to pray.Nasai (1040) also narrated it through the route of Abdul-Hameed, in abridged form.Tirmidhi said, "Hasan sahih."Ibn Hibban (1866) said, "This report was heard by Muhammad bin Amr bin Ata from Abu Humayd Saadi, and it was also heard by Abbas bin Sahl bin Saad Saadi from his father, so both routes are preserved."I say, that is after he narrated it from Muhammad bin Ishaq bin Ibrahim, freedman of Thaqif, who said, Walid bin Shuja Sakuni told us, Abu Bishr told us, he said, Abu Khaythama told us, he said, Hasan bin Hurr told me, he said, Isa bin Abdullah bin Malik told me, from Muhammad bin Amr bin Ata, one of the sons of Malik, from Abbas bin Sahl bin Saad Saadi, that he was in a gathering attended by his father, who was among the companions of the Prophet ﷺ, and in the gathering were Abu Hurairah, Abu Usayd, and Abu Humayd Saadi, from the Ansar, and they discussed the prayer.Abu Humayd said, I am the most knowledgeable among you about the prayer of the Messenger of Allah ﷺ. They said, Show us. So he stood to pray while they watched. He began by saying the takbir and raising his hands level with his shoulders, then said the takbir for ruku, raising his hands as well, then placed his hands firmly on his knees, neither raising his head up nor dropping it down. Then he raised his head and said, "Allah hears whoever praises Him, our Lord, to You belongs all praise." Then he raised his hands, then said, "Allah is greatest," and prostrated, resting upright on his palms, his knees, and the front of his feet while prostrating. Then he said the takbir and sat, resting tawarruk on one leg while keeping the other foot upright. Then he said the takbir and performed the second sajdah, then said the takbir and stood without sitting tawarruk. Then he returned and performed the second rakat, saying the takbir in the same way. Then he sat after the two rakats, until when he intended to rise, he said the takbir, then performed the last two rakats. When he finished with the tasleem, he gave the salam to his right, saying, "Peace and the mercy of Allah be upon you," and gave the salam to his left, saying, "Peace and the mercy of Allah be upon you."Hasan bin Hurr said, Isa also told me, among what he related in that gathering, concerning the tashahhud, that he would place his left hand on his left thigh and his right hand on his right thigh, then point with a single finger during the supplication. End of report.This hadith was also narrated by Abu Dawud (733) from Ali bin Husayn bin Ibrahim, who said, Abu Badr (Shuja bin Walid) told us, Zuhayr Abu Khaythama told me it, in abridged form. Its isnad is hasan, for Shuja bin Walid has been criticized regarding his memory. However, Tahawi, in his commentary (1/261), faulted it on the grounds that "Muhammad bin Amr is not known to us, nor is his connection to Abu Humayd established, because his hadith indicates that he was present with Abu Humayd and Abu Qatada, yet the death of Abu Qatada occurred a long time before that, since he was killed alongside Ali ﷺ, and Ali performed the funeral prayer over him, so how does the age of Muhammad bin Amr bin Ata fit with this?" End of quote.Hafiz said in "Talkhis" (1/223), "Muhammad bin Amr is Ibn Alqama bin Waqqas Laythi Madani, and he never met Abu Qatada, nor came close to that, for he only narrates from Abu Salama bin Abdul-Rahman and other senior successors. As for the Muhammad bin Amr from whom Abdul-Hameed bin Jafar narrated, he is Muhammad bin Amr bin Ata, a senior successor. Bukhari affirmed that he heard from Abu Humayd and others, and cited the hadith through his route." Then he said, "This hadith has other routes from Abu Humayd, in some of which he names, among the ten, Muhammad bin Maslama, Abu Usayd, and Sahl bin Saad. This is the narration of Ibn Majah, from the hadith of Abbas bin Sahl bin Saad, from his father. Ibn Khuzayma also narrated it through several routes." End of quote.I say, it is as he said. Ibn Majah (863) narrated it from Muhammad bin Bashshar, who said, Abu Amir told us, who said, Fulayh bin Sulayman told us, who said, Abbas bin Sahl Saadi told us, he said, Abu Humayd, Abu Usayd Saadi, Sahl bin Saad, and Muhammad bin Maslama gathered together and discussed the prayer of the Messenger of Allah ﷺ. Abu Humayd said, I am the most knowledgeable among you about the prayer of the Messenger of Allah ﷺ, and he related it in abridged form.It was also narrated by Abu Dawud (734) and Tirmidhi (260), both through the route of Fulayh bin Sulayman, in abridged form, with some of them adding to what others said. Tirmidhi said, "Hasan sahih."As for Hafiz's statement, "Ibn Khuzayma narrated it through several routes as well," meaning he narrated it through multiple routes, one of which includes Muhammad bin Amr bin Ata, see Ibn Khuzayma (587).As for Abdul-Hameed, Ibn Hibban said of him in his Sahih (3/172), "One of the reliable and precise narrators. I have examined his reports and never found him alone in transmitting a rejected hadith without being corroborated. Fulayh bin Sulayman and Isa bin Abdullah bin Malik, from Muhammad bin Amr bin Ata, from Abu Humayd, both agree with Abdul-Hameed bin Jafar in this report." End of quote.For more, see Minna Kubra (1/491–493).