Placing the hands and keeping the feet upright in prayer

Amir bin Sa'd narrates from his father (Sayyiduna Sa'd bin Abi Waqqas, may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) ordered placing both hands (on the ground) and keeping both feet upright (on the toes) in prayer.
This hadith is sahih on the condition of Imam Muslim, but the two Shaykhs did not record it, and this hadith is also established as sahih on Imam Muslim's condition with clearer wording than this:

Amir bin Sa'd bin Malik narrates from his father that the Messenger of Allah (peace and blessings be upon him) ordered placing both palms (on the ground) and keeping both feet upright in prayer.

Abu Salih says: I was with Sayyidah Umm Salamah (may Allah be pleased with her) when a young relative of hers with long hair came in and stood up to pray, and he began to blow (to clear the dust from the place of prostration). She said: My son, do not blow, for I heard the Messenger of Allah (peace and blessings be upon him) say to a black slave of ours: "O Rabah, let your face get dusty (that is, do not brush the dust away)."
This hadith has a sahih chain, but the two Shaykhs did not record it.

Sayyiduna Samurah bin Jundub (may Allah be pleased with him) relates that the Messenger of Allah (peace and blessings be upon him) forbade istifaz in prayer (that is, prostrating restlessly or not resting the limbs fully on the ground).
This hadith is sahih on the condition of Imam Bukhari, but the two Shaykhs did not record it.

Sayyiduna Hudhayfah (may Allah be pleased with him) relates that when the Messenger of Allah (peace and blessings be upon him) raised his head from prostration, he would make this supplication: 'Rabbighfir li' (O my Lord, forgive me).
This hadith is sahih on the condition of the two Shaykhs, but they did not record it.