Musannaf Ibn Abi Shayba 13:1382

Abu Bakr narrated to us, he said: Isma'il ibn 'Ulayyah narrated to us, from Layth, from 'Abd al-A'la, from Abu 'Abd al-Rahman, from 'Ali: "And give them from the wealth of Allah which He has given you." He said: It is the quarter of the first of its installments.