Musannaf Ibn Abi Shayba 5:665

'Abd al-A'la narrated to us, from Abu Ishaq, from al-Zuhri, from Humayd ibn 'Abd al-Rahman, from 'Abd al-Rahman ibn al-Qari, who was in charge of the public treasury (Bayt al-Mal) during the time of 'Umar along with 'Ubayd Allah ibn al-Arqam. When the stipends (al-'ata') were distributed, 'Umar would gather the wealth of trade, then calculate its immediate and deferred portions, then he would take the Zakat from the present and the absent.