Musannaf Ibn Abi Shayba 8:722

Abu Bakr narrated to us, he said: Waki’ narrated to us, from ‘Imran bin Hudayr, from Abu Mijlaz, who said: I threw the pebbles at the Jamarat, but I did not know how many I had thrown. So I asked Ibn ‘Umar, but he did not answer me. Then Ibn al-Hanafiyyah passed by me, and I asked him. He said: "O servant of Allah, there is nothing greater upon us than the prayer, and if one of us forgets [in it], he repeats it." So I informed Ibn ‘Umar [of what he said], and he replied: "Indeed, they are a household that has been granted understanding."