Lech Lecha: Chazak!

I've heard many people poke fun at Avraham Fried's famous song "Chazak", which comes from this week's haftarah. The song is taken primarily from Yeshaya 41:6, which states: "איש את רעהו יעזרו ולאחיו יאמר חזק" - "Each man helps his friend, and to his brother says, 'Be strong!'" The alleged irony is that the context of the passuk in the haftara is the idolatrous nations preparing for war against HaShem by constructing their idols.

It should be pointed out, though, that Avraham Fried's choice of this passuk is probably based on Midrash Rabbah (I have written down 44:8, but according to this edition, it's 43:3), which expounds the episode as a reference to Avraham's battle against the four kings. I recall the specific passuk in question as being expounded as a reference to Malkitzedek and Avraham, but I don't see this in the Midrash Rabbah.

If one wishes to point out an irony in a song, one would do better to look at the Shabbos song of "Yom Shabbason", in which the second part of the chorus, "V'sham yanuchu yegi'ei cho'ach" - "And there shall rest the weary", is taken from Iyov 3:17, where Iyov uses the pronoun "sham" to refer to the grave.