"He did not dispel the pillar of cloud in the day, and the pillar of light at night": We are hereby apprised that before the pillar of cloud had set, the pillar of light had risen. Variantly: Scripture hereby comes to teach us proper deportment for Sabbath eve (i.e., that the Sabbath candles should be lit before the day has departed).
He Did Not Dispel the Pillar of Cloud in the Day
Mekhilta Tractate Vayehi Beshalach 1:28