Rashi on Exodus 14:20/רש"י על שמות י״ד:כ׳

1ויבא בין מחנה מצרים AND IT CAME BETWEEN THE CAMP OF EGYPT — A parable: it may be compared to one who is proceeding on a journey, his son walking in front of him. If, now, brigands come to capture him (the son), he takes him away from in front of him and places him behind himself. If a wolf then comes behind him he places him again in front. If brigands come in front of him and wolves behind him, he places him on his arm and fights against them. Thus did God do for Israel, as it says, (Hosea 11:3) “I led Ephraim — He took them upon His arms” (Mekhilta).

2ויהי הענן והחשך AND THERE WAS CLOUD AND DARKNESS to the Egyptians.

3ויאר AND IT — the pillar of fire — ILLUMINATED the night for the Israelites, and went before them as was its way to go every night, whilst the darkness of the cloud was turned towards the Egyptians.

4ולא קרב זה אל זה SO THAT ONE APPROACHED NOT ANOTHER — [This does not mean that one person did not approach another but]: this camp did not approach that camp (Mekhilta).