Musar zu Ijow 29:17

Until now we have told of the evils of cruelty, but there are places where it is necessary to conduct one's self with cruelty against the wicked, as Job said: "And I broke the jaws of the unrighteous, and plucked the prey out of his teeth" (Job 29:17), and as the Torah itself has commanded us to execute the wicked and to lash them. And thus did our rabbis say: "He who does not want to build a Sukkah, nor make fringes for his tallit… nor fix a Mezuzah on his doorpost deserves to be beaten within an inch of his life" (Ketuboth 86a). And all this requires cruelty of a sort — to pursue the wicked and to press heavily upon them in order to restore them to good conduct.