And on that very day is identical with verse 41 and refers to the same day of the exodus. The LORD brought out is literally “Yahweh caused to go out.” The people of Israel, as elsewhere, is literally “the sons of Israel,” meaning “the Israelites.” Out of the land of Egypt may be shortened to “out of Egypt.” By their hosts is better understood as “by their divisions” (New International Version), or “troop by troop” (New Jewish Publication Society’s Tanakh). Good News Translation simply uses only “tribes,” and Contemporary English Version has “families and tribes,” but the word hosts is a military term. (See the comment at verse 17.) They were probably not organized into “armies” (Jerusalem Bible, New Jerusalem Bible), and Revised English Bible‘s “mustered in their tribal hosts” seems a bit too wordy. Translator’s Old Testament has “as a disciplined group.” A possible rendering taking into account the idea of “organization” is the following: “On that same day the LORD caused the Israelites to go out of Egypt in an orderly way, tribe by tribe.”

Quoted with permission from Osborn, Noel D. and Hatton, Howard A. A Handbook on Exodus. (UBS Helps for Translators). New York: UBS, 1999. For this and other handbooks for translators see here .