Musannaf Ibn Abi Shaybah 6901 — Those who said: he prays in twos

Sayyiduna Ibn Abbas and Sayyiduna A'idh bin Amr (may Allah be pleased with them both) said: When you have prayed witr in the early part of the night, do not pray it in the last part. When you pray witr in the last part of the night, do not pray it in the early part of the night.