Musar על ישעיהו 56:11

The most serious of all these offenses are: the use of crude speech, speaking irreverently about Torah scholars and behaving forcefully and uncooperatively in matters of litigation. But there is another form of conduct for which the Heavenly court also imposes a ban that is more serious than any of these. That is, speaking to others brazenly and without any shame at all. For this offence the ban discussed above is not sufficient, therefore his soul is reincarnated as a dog. This is the meaning of the expression, “And the brazen-souled dogs” (Yeshayahu 56:11). And if you suppose that being reincarnated as a dog is a minor punishment, consider that the same punishment is meted out to one who has relations with a married woman, Heaven spare us.