EXOD38 … one should be zealous on God's behalf against sinners and evildoers--to war with them and chastise them--as our Rabbis of blessed memory have said (Sanhedrin 81b: "If one cohabits with an Aramean woman, zealots may strike him down." Moshe was zealous on God's behalf against the Egyptian, as it is written [this verse]: "And he smote the Egyptian." And so we find with Eliyahu, who said (I Melachim 19:10): "I have been zealous on behalf of Hashem, the God of hosts, for the Children of Israel have forsaken Your covenant." And it is so written of Pinchas (Bemidbar 25:11): "Because he was zealous for My sake in their midst." And the Blessed One rewarded him for this, as it is written (ibid.: 12): "Behold, I give to him my covenant of peace" and it is written (Devarim 1:17): "Do not be afraid of any man." One who fears the Blessed One will give his life for the sanctification of His name, as it is written (Shemos 32:26): "Whoever is for Hashem, let him come to me; and all the sons of Levi gathered themselves together to him." And it is written (Bemidbar 25:7): "And Pinchas, the son of Elazar, the son of Aharon the Priest saw, and he arose from the midst of the congregation and took a spear in his hand." All who fear Hashem and who are pure of heart are duty-bound to stir a zealousness on behalf of Hashem when they see "the hands of the princes and rulers in crime." Our Rabbis of blessed memory have said (Bereshis Rabbah 26:5): "Any breach which is not made by the great is not called a breach, as it is written (Ezra 9:2): 'And the hands of the princes and the rulers were in this crime first.'"