Promise 33 from Numbers 25:11-13

Num. 25:11-13 - "'Phinehas, the son of Eleazar, the son of Aaron the priest, has turned away My wrath from the son of Israel in that he was jealous with My jealousy among them, so that I did not destroy the sons of Israel in My jealousy. Therefore say, 'Behold I give him My covenant of peace; and it shall be for him and his descendants after him, a covenant of a perpetual priesthood, because he was jealous for his God and made atonement for the sons of Israel.'"

God is a jealous God, He will go to extremes to protect His people from dividing their attention between Him and others. He will also go to extremes to bless those who are equally jealous for those things He is jealous for. Because of Phinehas' behaviour of killing the man who brought the Midianite women into the camp, knowing that the man's action would cause grave consequences later on down the road, God blessed Phinehas and all those who come after him in his family with peace and of priesthood. Meaning, they would never have to fight in war. Phinehas, himself made atonement for the sons of Israel, this made God happy. He loves it when we step up to bat and interceded for others so that they would come into right relationship with God. When we do that, God blesses us as well. He gives us His peace.