Narrated to us Abu Bakr ibn Abi Shaybah, narrated to us Waki', from Isma'il ibn Abi Khalid, from al-Zubayr ibn 'Adiyy, from Mus'ab ibn Sa'd, who said: I bowed in prayer and placed my hands together like this—meaning he clasped them and placed them between his thighs—so my father said: "We used to do this, then we were commanded to [place our hands] on the knees."