In spite of his great success, Abraham nevertheless was concerned about the issue of the war. He feared that the prohibition against shedding the blood of man had been transgressed, and he also dreaded the resentment of Shem, whose descendants had perished in the encounter. But God reassured him, and said: "Be not afraid! Thou hast but extirpated the thorns, and as to Shem, he will bless thee rather than curse thee."
So it was. When Abraham returned from the war, Shem, or, as he is sometimes called, Melchizedek, the king of righteousness, priest of God Most High, and king of Jerusalem, came forth to meet him with bread and wine. And this high priest instructed Abraham in the laws of the priesthood and in the Torah, and to prove his friendship for him he blessed him, and called him the partner of God in the possession of the world, seeing that through him the Name of God had first been made known among men.
But Melchizedek arranged the words of his blessing in an unseemly way. He named Abraham first and then God. As a punishment, he was deposed by God from the priestly dignity, and instead it was passed over to Abraham, with whose descendants it remained forever.