Musannaf Ibn Abi Shayba 13:164

'Abdullah ibn al-Mubarak narrated to us, from Ma'mar, from al-Zuhri, who said: A man gave one hundred dinars in charity to his son, and they were partners, and the wealth was in the hand of his son. He said: It is not permissible until he takes possession of it. Abu Bakr and 'Umar decreed: If he does not take possession, then there is nothing for him.