‘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 every part of his body would settle in place. Then he would recite, then he would 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.’”
* Meaning that he would plant them in such a way that they were facing the Qiblah.
** Mutawarrikan: i.e., sitting with the left foot brought forward so that one's buttocks are in direct contact with the ground.