And it shall be a perpetual statute for them: This sentence is similar to the end of verse 10, which may indicate that it belongs as a conclusion to verses 11-20 (so Ashley, page 374). However, this sentence also acts as a transition to verses 21b-22, which seem almost like an appendix to the discussion of the chapter as a whole. This is because these verses deal with the person who carries out the ritual of purification, first mentioned in verses 18-19. The purifier too becomes unclean during this process and must himself take care of his defiled state before reentering the camp of Israel. For perpetual statute, see verse 10. The pronoun them refers to the Israelites. The LORD is still speaking to Moses and Aaron about the Israelites. Good News Translation refers to the Israelites in second person by using the pronoun “You.” This is in line with Good News Translation‘s restructuring of the LORD’s speech in this chapter (see the comments on verses 2-3). In order to make the referent clear here, the pronoun them may be rendered “the Israelites” or “you, Israelites.”

He who sprinkles the water for impurity shall wash his clothes; and he who touches the water for impurity shall be unclean until evening: See the comments on verse 7. For the Hebrew verb rendered sprinkles, see verse 4 and 8.7; for the water for impurity, see verse 9.

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 .