Exodus 14:19-20

19And the Angel of God, who went before the camp of Israel, moved and went behind them; and the pillar of cloud went from before them and stood behind them.

20So it came between the camp of the Egyptians and the camp of Israel. Thus it was a cloud and darkness to the one, and it gave light by night to the other, so that the one did not come near the other all that night.