And of Levi he said: again it is better to say something like “About the tribe of Levi he said” (Good News Translation) or “About the people of the tribe of Levi….”

Give to Levi: as the Revised Standard Version footnote states, this is from the Septuagint; it is not found in the Hebrew text as we have it. New Revised Standard Version follows Revised Standard Version but adds a Qumran manuscript in support of this addition. It is recommended that it be kept in translation. Hebrew Old Testament Text Project ({C} rating) prefers the following text:
to Levi your Thummim were given,
and your Urim (to a man, your holy one).

Levi … thy godly one: the name Levi and the expression thy godly one are parallel; thy godly one may be translated “the one who is dedicated to God,” or “you people who are God’s priests.”

The Thummim and Urim were two objects (perhaps stones) used by the priest to determine God’s will (see Exo 28.30; Lev 8.8; 1 Sam 14.41-42). It is not known precisely how they were used. It may be good to give this information in a footnote, as Good News Translation does: “urim and thummim: Two objects used by the priest to determine God’s will.” Contemporary English Version leaves out the reference to Urim and Thummim; but it is recommended that translators retain it.

Thou didst test … thou didst strive: these are parallel and close in meaning. To test someone is to subject that person to hardships and difficulties in order to reveal that person’s character. Another way to express this is “You caused them to endure hardships at Massah, to see what kind of people they were” (see also 8.2). To strive is to fight against. Good News Translation “proved them true” seems too far wide of the mark.

For Massah see 6.16; 9.22; Exo 17.7; for Meribah see 32.51; Exo 17.7.

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 .