Malki-Tzedek, King of Shalem, brought out bread and wine.
Avraham called that place God Yireh.
Both of these saintly men – Malki-Tzedek, who was Shem, son of Noach, and his descendant Avraham – were referring to the site upon which stands Jerusalem (whose biblical name is Yirehshalem).
When God wished to name His holy city, He faced, as it were, a Divine dilemma.
“If I call it Yireh like Avraham did, the righteous Shem will feel slighted, and if I call it Shalem like Shem did, the righteous Avraham will feel slighted. I will therefore call it Yireh-Shalem like both of them called it.”
Shalem means both peace and perfection, while Yireh, as Targum Onkelos translates, means human service of God. Only when man serves God can he hope to achieve the peace and perfection symbolized by Yirehshalem (Bereishit Rabbah 56:10).