Sunan an-Nasa'i 1031

Nuh ibn Habib informed us: Ibn Idris reported to us, from ʿAsim ibn Kulayb, from ʿAbd al-Rahman ibn al-Aswad, from ʿAlqamah, from ʿAbdullah, who said: “The Messenger of Allah (peace and blessings be upon him) taught us how to pray. He stood and said the takbir. When he was about to bow, he joined his hands between his knees and bowed. News of this reached Saʿd, who said: ‘My brother has spoken the truth. We used to do that, then we were commanded to do this’—meaning, to hold the knees.”