Ma'la bin Asad al-'Ami معلى بن أسد العمي أبو الهيثم البصري · The Book on Salat (Prayer)

"The Prophet ordered placing the hands (on the ground) keeping the feet erect. (by resting feet on the toes and making the tips of the toes facing the Qiblah)."

"The Prophet ordered placing the hands (on the ground)." And he mentioned in it: "From his father."