Musannaf Ibn Abi Shaybah 6918 — Those who delayed their witr

Sayyiduna Ali (may Allah be pleased with him) said: The Prophet (peace and blessings be upon him) used to pray witr at the time of the adhan, and he would pray the two rak'ahs at the time of the iqamah. In Salam's narration there is the addition that he would pray witr at the time of the first adhan. Salam said: I heard Abu Ishaq once say that he would pray witr at the rising of dawn.