Musnad Ahmad 26:503

Ibn Fudayl narrated to us, Layth narrated to us, from ‘Abd al-Rahman ibn al-Aswad, from his father, from ‘Abdullah, who said: The Prophet, peace and blessings of Allah be upon him, went out for a need of his, and he said: "Bring me something to clean myself with, and do not bring me any bone or dung." Then I brought him water, and he performed ablution. Then he stood and prayed, and he bowed, and he placed his hands together when he bowed, and he placed them between his thighs.