DEUT1276 Do not offer on the Altar an animal that was used as payment to a harlot or as payment for any forbidden relations. So, too, an animal that was traded for a dog is unfit as an offering. Of course, the disqualification applies to animals that otherwise are fit to be offerings, for other animals are barred from the Altar in any case. As noted earlier ([[EXOD940]] Exodus 25:8 sanctuary CHINUCH 62-5), offerings are to purify the thoughts and improve the deeds of those who bring them. Harlotry is a low and vile transgression, so if the animal brought as an offense was payment to a harlot, the corrupting, impure thought of that sin is likely to enter the mind of the person bringing the offering, which would have destructive consequences. The idea is similar regarding an animal that was traded for a dog. Offerings provided atonement. As someone guilty of sin brings an offering, he is supposed to imagine that everything that happens to the offering should be happening to him, on account of his sin. The animal is slaughtered before his eyes. Afterwards it is cut into pieces. The one bringing the offering thinks, “That should have been me,” and the pain of experiencing these thoughts is part of his atonement. He realizes that Hashem, in His kindness, accepted an animal as an “exchange.” Hopefully, because of these thoughts, the sinner's heart will soften. He will regret his sin and his heart will be filled with firm resolve to not sin again. Therefore, no offering can be an animal that was traded for a dog, for dogs are known for their gall. They are insolent. Shame is foreign to them. If an animal traded for a dog is used as an offering, the mind and heart of the person bringing the offering might become infected with gall and shamelessness. There is a chance that his heart will not soften and he will remain stubborn and not regret his sin.