Midrasch zu Schemuel I 20:30

Similarly, it states: That I will cut off from thee the righteous and the wicked (Ezek. 21:8). The righteous ones were cut off because they did not try to restrain the wicked ones. That is why you find that King Josiah was held responsible for the acts of his generation, even though it is written concerning him: And like unto him there was no king before him (II Kings 23:25). How far should one go in reproving one’s neighbor? Rav said: Until his neighbor strikes him. Samuel contended: Until he curses him. R. Johanan held: Until he becomes angry. All three reached their conclusions from the same verse, where it is said: Then Saul’s anger was kindled against Jonathan, and he said unto him: “Thou son of perverse rebellion” (I Sam. 20:30). And then it is written: And Saul cast his spear at him to smite him (ibid., v. 33).