Musannaf Ibn Abi Shayba 13:2028

Abu Bakr narrated to us, he said: Ali bin Mushir narrated to us, from Layth, from Mujahid, from Ibn Umar, he said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever asks by Allah, then give to him. And whoever offers a gift to you of a trotter (of an animal), then accept it."