Rashi on Numbers 25:12/רש"י על במדבר כ״ה:י״ב

1את בריתי שלום [I GIVE TO HIM] MY COVENANT — PEACE — This means: I give him my covenant that it should be to him as a covenant of peace; just like a man who shows gratitude and friendliness to one who has done him a kindness. So here, too, the Holy One, blessed be He, expressed to him His peaceful feelings towards him.