Our Sages claim that Malki-Tzedek was identical with Noah's son Shem. (Midrash Aggadah) The reason that the Torah interrupts the report of Lot's rescue by reporting Malki-Tzedek's arrival is to contrast his behavior with that of the king of Sodom. Whereas Malki-Tzedek came with gifts and a blessing though Abraham had done nothing for him, the king of Sodom came empty-handed, although he owed Abraham a great debt of gratitude for having saved both his life and his kingdom. The Torah is only showing the difference between the behavior of the wicked and that of the just.

Malki-Tzedek conferred the priesthood upon Abraham...

"..and he was a priest of the Supreme G‑d." (ibid)

The emphasis on the word he indicates that only he was a priest, not his descendants. The priesthood was conferred upon Abraham as we know from the verse: "You are a priest forever." (Psalms 110:4) The Psalmist refers to the blessing conferred upon Abraham by Malki-Tzedek. I will still explain that Malki-Tzedek conferred the priesthood upon Abraham willingly. The words "of the Supreme G‑d," are necessary as there were many priests of many deities.

Our Sages claim that Malki-Tzedek lost his priesthood because he blessed Abraham before he blessed G‑d. [(Ibid. 14:19), (Ibid. 14:20), as in (Nedarim 32)] Accordingly we would have to understand the words: "and he was a priest" to mean that his priesthood was something of the past. He forfeited it by slighting G‑d. The fact that the Torah did not report the unfortunate wording of Malki-Tzedek's blessing until after hinting that he had already forfeited the priesthood is irrelevant because the Torah was not written till after the event.

We must try to understand what prompted Malki-Tzedek to commit such an error. Perhaps he thought that inasmuch as Abraham had come to recognize G‑d without parental or anyone else's guidance, he deserved to receive a blessing first and foremost. Afterwards he blessed the L-rd who had found pleasure in a human being such as Abraham. Malki-Tzedek may have wanted to teach us that G‑d only truly enjoys human beings who have first made it their business to please Him.

He expressed this thought by saying: "Blessed Abraham to the Supreme G‑d because he made himself be fit to be a servant of the L-rd. As a result he is blessed by the Supreme G‑d who had committed your enemies into your hands." [According to this, Malki-Tzedek's error consisted in using chronology as a guideline for the order in which he formulated his blessing. E.M.] Despite the good intention of Malki-Tzedek, this was an improper way of blessing. The servant never takes precedence over his master.

"And he blessed him and said, 'Blessed be Abram to G‑d' etc." (Gen. 14:19)

Here we need to understand whether the "Blessed be Abram" is the gist of the blessing intended by "And he blessed him"? For if so, why did the Torah have to use such introductory words? Rather, I believe that the words 'bless Abram' allude to an additional blessing. Were this not so, the expression 'And he blessed him' should have been followed by the word 'lemor/saying.'

...but for Abraham, G‑d would not really have a true possession in either heaven or earth.

We must understand the matter as follows. First Malki-Tzedek bestowed a blessing on Abraham which pertained to his personal wellbeing such as that his enemies should not be able to harm him, etc. Next he blessed him wishing him spiritual development – which was a blessing directed to G‑d who should allow Abraham to be His true servant. By being successful as a servant of the L-rd, G‑d Himself would be perceived by man as the owner of not only the heavens but also of the earth. He wished him that through him his descendants would acquire eternal life so that heaven and earth would endure forever. Our Sages (compare Zohar 1:89) have expressed all this when they said that but for Abraham, G‑d would not really have a true possession in either heaven or earth.

Even the closing words of Malki-Tzedeks' blessing, i.e. "Who delivered your enemies into your hands" which ostensibly seems to be a blessing conferred by G‑d to Abraham, are a blessing conferred upon G‑d. G‑d considers Himself blessed through the existence of a human being such as Abraham.

[Selected with permission from the five-volume English edition of "Ohr HaChaim: the Torah Commentary of Rabbi Chaim Ben Attar" by Eliyahu Munk.]