This is perhaps the single most important identification Targum Pseudo-Jonathan makes in the Abram cycle. On (Genesis 14:18) the Aramaic declares: Malka Zadika, who was Shem bar Noah, the king of Yerushalem, came forth to meet Abram.
Malkizedek is Shem. The son of Noah. The survivor of the Flood whose name means Name itself.
This identification, preserved also in the Babylonian Talmud (Nedarim 32b) and in Bereshit Rabbah 43:6, solves a mystery the Hebrew Bible leaves hanging. Who is this sudden king of Salem, priest of El Elyon, the Most High? The Targum answers: he is the last living link to the pre-flood world, the son of Noah who inherited his father's priestly knowledge and kept the worship of the one God alive through the centuries between the Flood and Abram.
And he is king of Yerushalem. Jerusalem. The Aramaic places the city of David into the patriarchal narrative. Shem-Malkizedek rules from the mountain that will one day hold the Temple. The priesthood that will be consolidated in Aaron's line (Exodus 28:1) already has a pre-history in the oldest living son of Noah, offering bread and wine to a returning warrior.
The Targum adds one more detail: in that time he ministered before Eloha Ilaha. God the Most High. Shem's priesthood is intact. He brings out bread and wine — the offerings that will later stand at the center of Jewish worship (Exodus 29:40) — and serves them to Abram as a priest serves a covenantal brother.
Abram is meeting his own ancestor. Ten generations separate them, and yet here they stand on the same hill, one coming from Eden's memory, the other going toward Sinai's promise. The chain holds.