Sahih Ibn Khuzaymah

Hazrat Muhammad bin Amr bin Ata says that I heard Sayyiduna Abu Humayd Sa’idi (may Allah be pleased with him) in the presence of ten companions of the Messenger of Allah (peace and blessings be upon him), and he said: "I know the prayer of the Messenger of Allah (peace and blessings be upon him) better than all of you." They said: "Neither is your companionship with the Messenger of Allah (peace and blessings be upon him) older than ours, nor do you surpass us in following and emulating him." He said: "Why not (I know the prayer of the Messenger of Allah (peace and blessings be upon him) better than you)?" They said: "(If that is the case) then present (describe the prayer of the Messenger of Allah (peace and blessings be upon him))." He said: "When the Messenger of Allah (peace and blessings be upon him) would stand for prayer, he would raise both his hands up to his shoulders, then say « اللهُ أَكْبَرُ ». Then he would stand completely straight until every bone would settle in its place. Then he would recite, then raise both hands and, saying « اللهُ أَكْبَرُ », would bow (ruku’), placing both palms on his knees, and would neither raise his head nor lower it excessively (but keep it in a moderate, level position). Then the Messenger of Allah (peace and blessings be upon him) would say « سَمِعَ اللهُ لِمَنْ حَمِدَهُ » and raise both hands up to his shoulders in complete moderation, until every bone would return to its place. Then the Messenger of Allah (peace and blessings be upon him) would say « اللهُ أَكْبَرُ » and prostrate, keeping his arms away from his sides. Then when he would raise his head (from prostration), he would fold his left foot and sit on it, and keep the toes of his right foot upright. Then when the Messenger of Allah (peace and blessings be upon him) would stand, he would do the same in the second rak’ah. Then when the Messenger of Allah (peace and blessings be upon him) would rise after the tashahhud of two rak’ahs, he would do as he did at the beginning of the prayer (i.e., raise his hands up to his shoulders saying « اللهُ أَكْبَرُ »)."

Sayyiduna Abdullah bin Umar (may Allah be pleased with him) narrates that indeed the Sunnah way in prayer is that when you sit in prayer, you should lay down your left foot and keep your right foot upright.

Sayyiduna Abdullah bin Umar (may Allah be pleased with him) narrates that among the Sunnah methods of prayer is that you spread your left foot and keep your right foot upright. And he said that when the Noble Prophet (peace and blessings of Allah be upon him) used to sit in prayer, he (peace and blessings of Allah be upon him) would lay down his left foot and keep his right foot upright. Imam Abu Bakr (may Allah have mercy on him) says that in my opinion, the addition of these words in the narration of Imam Ibn Uyainah is not established: that when the Noble Prophet (peace and blessings of Allah be upon him) used to sit in prayer, he (peace and blessings of Allah be upon him) would lay down his left foot and keep his right foot upright.