זוהר בראשית — דף צב ע”ב

Rabbi Abba arrives with his son Rabbi Yaakov at the village of Tarsha and asks the host for a rooster so as to rise at midnight. The host shows him a vessel of water that drips and a wheel that rumbles at exactly midnight, made by an elder who studied Torah every night. At midnight they hear the host say “At midnight I rise to give You thanks” and explain why it says “ḥatzot layla” and not “at midnight”: the Holy One, blessed be He, then enters the Garden of Eden and the harsh judgments below are not found. He cites Abraham and Egypt and links David to kingship. His young son explains that the first half is judgment and the second is kindness, and Rabbi Abba blesses him.