Sayyiduna Jabir bin Abdullah (may Allah be pleased with him) reports that the Messenger of Allah (peace and blessings be upon him) said: Whoever among you thinks that he will not be able to wake up in the last part of the night, then he should perform Witr at the beginning of the night. But whoever thinks that he will wake up in the last part of the night, then he should perform Witr at its end, because the prayer in the last part of the night is attended by the angels and it is the best.

Aswad bin Yazid says: I asked Umm al-Mu'mineen Sayyida Aisha (may Allah be pleased with her): At what time do you perform Witr? She said: I do not perform Witr until the muezzins have given the calls to prayer, and they give these calls after the rising of Fajr. The Messenger of Allah (peace and blessings be upon him) had two muezzins: Sayyiduna Bilal (may Allah be pleased with him) and Sayyiduna Amr bin Umm Maktum (may Allah be pleased with him). The Messenger of Allah (peace and blessings be upon him) said: When Amr gives the call to prayer, you may eat and drink, because he is a blind man, but when Bilal gives the call to prayer, then stop eating and drinking, because Bilal does not give the call until the morning has arrived.