Nehemiah 10:36

the firstborn of our sons The firstborn of the children of Israel -from a month old" were redeemed -for the money of five shekels, after the shekel of the sanctuary." Numbers 18:16; cf. Exodus 13:13; Exodus 34:20.

of our cattle, as it is written in the law The firstlings of oxen, sheep and goats were not redeemed; they were holy; their fat was offered as a burnt offering; the flesh was the portion of the priests. See Numbers 18:17-19. But the firstborn of all unclean beasts were redeemed for a price. Cf. Exodus 23:19; Numbers 18:15.

herds … flocks i.e. the goats and sheep mentioned in Numbers 18:17.