This verse refers to the events told in 20.2-13.

Because you rebelled against my word …: See 20.24. The conjunction because introduces why God will not allow Moses to enter the Promised Land. It is because he and Aaron disobeyed God’s command by failing to make it clear that it was God who brought forth water from the rock rather than themselves. As in 20.24, the Hebrew pronoun for you is plural, referring to Moses and Aaron. In many languages this will have to be made explicit by saying “both of you” (Good News Bible, Contemporary English Version, New International Version; similarly New Living Translation) or “you and Aaron” (Revised English Bible). You rebelled against my word is literally “you rebelled against my mouth,” as in 20.24.

In the wilderness of Zin: As mentioned at 13.21 (see the comments there), the Hebrew form of the name Zin is literally tsin, starting with a different sound than z or s. The rules for transliterating proper names should be made for the entire Old Testament, for example, whether to base such transliteration upon the actual Hebrew sounds or those of English (or the major language of wider communication in the region of the target language).

During the strife of the congregation: The Hebrew word for strife is meribah, which became the name of the place where the Israelites contended with God because of the lack of water (see the comments on 20.13). The Hebrew word for congregation (ʿedah) is better rendered “community” (Good News Bible; see 1.2). For this whole phrase Good News Bible has “When the whole community complained against me at Meribah.”

To sanctify me at the waters before their eyes: See the comments on 20.12. Good News Bible translates this clause as an independent one, saying “you refused to acknowledge my holy power before them.” New Living Translation expresses its meaning more accurately with “you failed to demonstrate my holiness to them at the waters,” and so does New Century Version with “You did not honor me as holy before the people at the waters of Meribah.” The phrase at the waters does not occur in 20.12. There is no reason to leave it untranslated here, as Good News Bible has done. The Septuagint and the Peshitta include the negative word “not” in this clause to make it more emphatic.

These are the waters of Meribah of Kadesh in the wilderness of Zin is literally “They [are/were] the waters of Meribah [at] Kadesh [in] the wilderness of Zin.” This sentence is probably a comment of the author (or editor) of Numbers concerning the location of the water provided by the LORD, so it is not part of the LORD’s words. Contemporary English Version and NET make it part of the LORD’s words, which we do not recommend. For the waters of Meribah, see the comments on 20.13 and 24. For the town of Kadesh, see 13.26 and the introductory comments on 20.1–21.35.

New Jewish Publication Society Version‘s slight restructuring of this verse makes it a helpful model, which is:
• For, in the wilderness of Zin, when the community was contentious, you disobeyed My command to uphold My sanctity in their sight by means of the water. Those are the Waters of Meribath-kadesh, in the wilderness of Zin.

In some languages it will be more natural to break the first sentence of this verse into two (so Good News Bible, Bible en français courant, PV). A model that does this is:
• For, in the wilderness of Zin, when the community quarreled with me, you both rebelled against my command. You did not maintain my holiness before the people at the waters. Those were the Waters of Meribah (meaning ‘Quarrel’) at Kadesh in the wilderness of Zin.

Quoted with permission from de Regt, Lénart J. and Wendland, Ernst R. A Handbook on Numbers. (UBS Helps for Translators). Miami: UBS, 2016. For this and other handbooks for translators see here .