Musar על מכות 45:19

Also this trait must a person practice with his fellow. Even if he is an evildoer that is plagued with afflictions, he shall not hate him - as once he has been debased, behold he is like your brother (Makkot 23a). And he [should] bring close the downtrodden and punished and have mercy upon them. And just the opposite, he should save them from the hand of the enemy, and he should not say, "It is his iniquity that caused it to him." But rather, he should have mercy upon him with this trait, as I have explained.