It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that when the Prophet (peace and blessings be upon him) would perform the two Sunnah rak‘ahs of Fajr, he would lie down until he began to snore. The narrator says that we used to say to ‘Amr that the Messenger of Allah (peace and blessings be upon him) said:“My eyes sleep but my heart does not sleep.”