The Levites who carried the ark of the covenant of the LORD: see verse 9; 10.8.

Put it by the side of the ark: the ark or “sacred box” itself was in the Most Holy Place in the “tent of meeting,” which was separated by a curtain from the larger Holy Place (Exo 26.33-34; 40.16-21). While this book was to be placed by the side of the ark, the two stone tablets containing the Ten Commandments were placed inside the ark (10.2, 5; Exo 40.20).

A witness against you: as it stands in Hebrew and translated literally in Revised Standard Version, Moses is talking to the Levites, and what he says in verses 26-27 and 29 is directed at them. But this seems hard to believe. Moses is speaking about all the Israelites, as Yahweh had done in verses 16-22. Good News Translation makes the appropriate changes by having at the end of verse 26 “… as a witness against his people,” then using the third plural in verse 27 and introducing “the people” as the subject in verse 29. Bible en français courant and Nova Tradução na Linguagem de Hoje do the same, and translators may wish to follow their example. Die Bibel im heutigen Deutsch has done it differently by adding at the end of verse 26, after the closing quotation marks of Moses’ statement, the following words: “And turning to the people, he went on to say, ….” This is also a good model. In any case it should be clear that the denunciations in verses 26-27 and 29 are directed not only at the Levites but at all the Israelites.

Quoted with permission from Bratcher, Robert G. and Hatton, Howard A. A Handbook on Deuteronomy. (UBS Helps for Translators). New York: UBS, 2000. For this and other handbooks for translators see here .