Musannaf Ibn Abi Shayba 13:1439

Abu Bakr narrated to us, he said: Ibn ‘Ulayyah narrated to us, from Khalid, from Abu Qilabah, he said: Ibn ‘Umar was asked about the wealth of the orphan. He said: "It is guaranteed until you hand it over to him." He said: "Indeed, there was a surplus in it." He said: "Do with its surplus what you wish; it is guaranteed until you hand it over to him."