Nehemiah 10:36

Also the firstborn of our sons and of our cattle
Such as were unclean, as Aben Ezra notes, as the ass and are distinguished from clean ones mentioned in the following clause; now both these, their sons, and this sort of cattle, were to be redeemed by a price paid to the priests: as it is written in the law, ( Exodus 13:2 Exodus 13:13 ) ( Numbers 18:15 Numbers 18:16 ) ,

and the firstlings of our herds, and of our flocks;
clean cattle, which were to be offered, ( Numbers 18:17 Numbers 18:18 ) ,

to bring to the house of our God, unto the priests that minister in the
house of our God;
a price for the one sort, and the other for sacrifice.