Silsilat al-Ahadith al-Sahihah

Sayyiduna Anas (may Allah be pleased with him) narrates that the eyes of the Messenger of Allah (peace and blessings of Allah be upon him) would sleep, but his heart would remain awake.

It is narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that the Noble Prophet (peace and blessings of Allah be upon him) said: "My eyes sleep but my heart does not sleep."

Ata says that the Prophet Muhammad (peace and blessings be upon him) said: "The eyes of the group of Prophets sleep, but their hearts do not sleep."