Numbers 3:41

And thou shall take the Levites for me,.... For his service, to minister to his priests, and serve in his tabernacle:

I [am] the Lord; who has a right to all, and can claim who he pleases for himself in a special manner, and therefore could and did take the Levites to himself:

instead of the firstborn among the children of Israel; these he had taken to him before, and ordered to be sanctified unto him, and for whom a redemption price was paid to his priests for the support of them, and the tabernacle service, and now it was his will to make an exchange of these for the Levites:

and the cattle of the Levites, instead of all the firstling among the cattle of the children of Israel: every firstling of clean cattle was the Lord's, and given to his priests, and the firstlings of unclean cattle were redeemed with a lamb, and which were given to the same; and now instead of these he requires the cattle of the Levites; not that they should be deprived of their use of them, or that they should be taken and sacrificed, but that they should be with them devoted to him, and they should possess them in his right.