The prayer of sleep instituted, according to the hours, to commemorate the laying down of the body of in the tomb. In churches and monasteries is said after vespers and before the of incense for the evening service. The DIDASCALIA (Qeladah, 1979) and Ibn al-‘Assal’s Kitab al-Qawanin (Book of Law) include among the seven prayers.

It appears that was initially confined to the Egyptian church, as THE GREAT does not include it in his earlier text of prayers. Instead, he divided the sext (the sixth hour) into two parts: the first preceding and the second following the evening meal, to bring the total number of prayers to seven.

Later, however, chose to add after vespers, incorporating with it “At midnight I will rise to give thanks unto Thee because of Thy righteous judgment.”