Verse 19 clearly indicates the divine source of the prophecy and forms the basis for the point that is made in verse 20 (God’s blessing upon Israel cannot be reversed). It also expresses a general principle, so verb forms that indicate habitual or repeated action should be used in some languages.
God is not man, that he should lie, or a son of man, that he should repent: Compare 1 Sam 15.29 with these two parallel lines. Balaam compares the God of Israel with human beings here. Man refers to men and women in this context, so it is better rendered “people” (Good News Bible). Son of man is literally “son of a human.” This idiomatic expression is used here in the sense of “human being” or “mere mortal”. A literal rendering of this phrase may give the wrong suggestion that it refers to some unnamed person’s child, or idiomatically, to some extraordinary individual (so Chewa). The Hebrew verb for repent is used here in the sense of “change[s] his mind” (Good News Bible, Contemporary English Version, New Living Translation). NBV says “come back on his decision.”
Has he said, and will he not do it? Or has he spoken, and will he not fulfil it?: These are parallel rhetorical questions to which the implied emphatic answer is “No.” New Jewish Publication Society’s Tanakh makes this implied answer clear by saying “Would He speak and not act, Promise and not fulfill?” In some languages it may be helpful to express the point these questions make by means of strong positive statements. Good News Bible uses statements, but some rhetorical underscoring should be included to duplicate the impact of the original poetry as follows: “Whatever he promises, he always does; He speaks, and it is done all the time.” This second half of the verse contrasts with the first half: God cannot fail like a human being; on the contrary, he always keeps his promises. The Hebrew verb for fulfil is literally “cause to arise” (see 1 Sam 3.12 for one other instance of this verb). This verb is used here to express that the LORD makes everything happen that he has previously said would happen. So he will most certainly fulfil his promises made through Balaam with reference to Israel.
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 .