וַיָּבֹ֞א בֵּ֣ין ׀ מַחֲנֵ֣ה מִצְרַ֗יִם וּבֵין֙ מַחֲנֵ֣ה יִשְׂרָאֵ֔ל וַיְהִ֤י הֶֽעָנָן֙ וְהַחֹ֔שֶׁךְ וַיָּ֖אֶר אֶת־הַלָּ֑יְלָה וְלֹא־קָרַ֥ב זֶ֛ה אֶל־זֶ֖ה כָּל־הַלָּֽיְלָה׃
它來到埃及營和以色列營之間；一邊是雲和黑暗，另一邊卻照亮了黑夜；整夜兩營彼此沒有接近。
Rashi
ויבא 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).
Sforno
ויבא (המלאך) בין מחנה מצרים ובין ישראל; in order to guide the two pillars.