Numbers 18:15

Context18:15 The firstborn of every womb which they present to the Lord, whether human or animal, will be yours. Nevertheless, the firstborn sons you must redeem, 1 and the firstborn males of unclean animals you must redeem.
Numbers 23:3
Context23:3 Balaam said to Balak, “Station yourself 2 by your burnt offering, and I will go off; perhaps the Lord will come to meet me, and whatever he reveals to me 3 I will tell you.” 4 Then he went to a deserted height. 5
1 tn The construction uses the infinitive absolute and the imperfect tense of the verb “to redeem” in order to stress the point – they were to be redeemed. N. H. Snaith suggests that the verb means to get by payment what was not originally yours, whereas the other root גָאַל (ga’al) means to get back what was originally yours (Leviticus and Numbers [NCB], 268).
2 tn The verb הִתְיַצֵּב (hityatsev) means “to take a stand, station oneself.” It is more intentional than simply standing by something. He was to position himself by the sacrifice as Balaam withdrew to seek the oracle.
3 tn Heb “and the word of what he shows me.” The noun is in construct, and so the clause that follows functions as a noun clause in the genitive. The point is that the word will consist of divine revelation.
4 tn The verb is the perfect tense with vav (ו) consecutive. This clause is dependent on the clause that precedes it.
5 sn He went up to a bald spot, to a barren height. The statement underscores the general belief that such tops were the closest things to the gods. On such heights people built their shrines and temples.