זוהר שמות — דף לז ע”ב

Rabbi Shimon explained the secret of midnight: the night does not perform its functions until it divides. Moses said 'around midnight', knowing that only in the second half does the Shekhinah rule. The crown Zot is also called Isha, for she was taken from Ish. As incense smoke carries different colors, the crown contains mercy and judgment in the same moment. 'The Lord struck every firstborn' signifies the arousal of Koh to execute judgment.