The topic of uncleanness preventing people from joining in the Passover celebration starts in this verse, so Good News Translation begins a new paragraph here.

And there were certain men who were unclean through touching the dead body of a man …: And is a literal rendering of the clause-initial Hebrew waw conjunction, which will be unnatural in many languages. New Revised Standard Version begins with “Now,” and Good News Translation uses the conjunction “But.” The Hebrew text does not focus on the male gender here, so certain men and the dead body of a man are better rendered “some people” and “a corpse” (Good News Translation). The Hebrew word for unclean refers to a state of ritual impurity, not to physical uncleanness (see 5.2). Who were unclean through touching the dead body of a man is literally “who were unclean through a [dead] body of a human.” New Jewish Publication Society’s Tanakh is similar with “who were unclean by reason of a corpse.” The Hebrew text lacks the verb touching. Revised Standard Version adds this verb to make explicit how the corpse could have made these people unclean (so also Good News Translation). If this verb is added, a translation should not imply that these people touched the corpse deliberately. Perhaps it happened in the case of a death in the family, but maybe not. A model that avoids this problem is “who were impure because of contact with a dead body” (similarly Levine). Some languages may even have a verb that limits the reference here to purely touching, with no implication as to whether that action was deliberate or not.

So that they could not keep the passover on that day: See verses 2-3. Since they were ritually impure because of contact with a corpse, they could not celebrate the Passover on the fourteenth day of the first month. Ritual impurity prevented people from any involvement in the festivals. Revised Standard Version expresses introduces the consequence here with the connector so that. Good News Translation has simply “and,” which is not as explicit.

And they came before Moses and Aaron on that day: The people who could not take part in the Passover due to their ritual impurity went to Moses and Aaron the day of the festival.

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 .