‘Abdallah b. Malik Ibn Buhaina* said that when the Prophet prostrated himself he spread out his arms so that the whiteness under his armpits was visible.
Narrated Maimuna said that when the Prophet prostrated himself he kept his arms so far away from his sides that if a lamb had wanted to pass under his arms it could have done so.
This is Abu Dawud’s wording, as explained in Sharh as-sunna with his isnad. Muslim has something to the same effect:
She said that when the Prophet prostrated himself, if a lamb had wanted to pass between his arms it could have done so.
Abu Huraira said that the Prophet used to say when prostrating himself, “O God, forgive me all my sins, small and great, first and last, open and secret.”
One night I missed God’s Messenger from the bed, and when I sought him my hand came on the soles of his feet while he was in the act of prostration with them raised, and he was saying, “O God, I seek refuge in Thy good pleasure from Thy anger, and in Thy forgiveness from Thy punishment, and I seek refuge in Thee from Thee.* I cannot reckon Thy praise. Thou art as Thou hast lauded Thyself.”
* This form of words indicates that God alone can give refuge from His wrath.
