Hasan al-Basri (may Allah have mercy on him) narrates: Ziyad appointed Kilab bin Umayyah al-Laythi over al-Ubullah. Sayyiduna Uthman bin Abi al-As (may Allah be pleased with him) passed by him and said: "O Abu Harun, what keeps you sitting here?" He said: "This man (Ziyad) has sent me over al-Ubullah." Sayyiduna Uthman (may Allah be pleased with him) said: "Shall I not narrate to you a hadith that I heard from the Messenger of Allah (peace and blessings be upon him)?" He (peace and blessings be upon him) said: "The Prophet of Allah Dawud (peace be upon him) would say to his family at a certain hour of the night: 'O family of Dawud, get up and pray, for this is an hour in which supplication is answered, except for a sorcerer or a tithe-collector (an oppressive official).'" So he (Kilab) boarded a boat immediately, then went back to Ziyad and asked to be relieved (of the post).
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 8342