Musannaf Ibn Abi Shayba 28:356

Mu'tamir ibn Sulayman narrated to us, from Dawud, from Yusuf ibn Sa'd, from Wuhayb, that Zayd ibn Thabit was in charge of the public treasury (Bayt al-Mal) during the caliphate of Uthman. He said: Uthman entered and saw Wuhayb helping them. He said, "Who is this?" He replied, "A slave of mine." He said, "I see him helping them; assign him two thousand." He said, "So he assigned him two thousand."