18. Thou shalt not bring the hire. This command has an affinity to the foregoing, for God, rejecting whatever is acquired by illicit and filthy traffic, teaches us that the utmost chastity is to be observed in sacred things; nor does He only refuse the hire of a whore, but also the price of a dog, lest the sanctity of the altar should be polluted by any impure oblation. Still the dog seems to be rejected in comparison with other animals out of contempt; for it was just as wrong to kill a pig as a dog, yet might the price of a pig be offered. The dog, therefore, is rejected not only as an unclean animal, but also as vile and contemptible. In sum, God would impress upon them the reverence due to His temple and altar.