זוהר שמות — דף קעג ע”א

The stars of the firmament praise the Holy One as long as they are visible, just like the higher angels. At nightfall evil spirits spread through the world and the Sitra Akhra rules; every person tastes one sixtieth of death. Three camps of holy angels give praise during the three watches of the night. Sixty myriads of angels bring sleep and separate impurity, except in the Land of Israel. Israel and the angels must repel the Sitra Akhra before approaching their Master.