Abraham's dilemma refers to the conflict between his moral intuition that infanticide is an immoral deed, and his required obedience to God to sacrifice his son. That it would be the Danish Lutheran, Kierkegaard, who would raise the question is not much of a surprise given how this may have been alluded to in the Lutheran Book of Concord itself.
In The Formula of Concord ~ Solid Declaration: VII the Holy Supper, it is argued:
Even as Abraham, when he hears God’s Word concerning offering his son, although, indeed, he had cause enough for disputing as to whether the words should be understood according to the letter or with a tolerable or mild interpretation, since they conflicted openly not only with all reason and with the divine and natural law, but also with the chief article of faith concerning the promised Seed, Christ, who was to be born of Isaac, nevertheless, just as previously, when the promise of the blessed Seed from Isaac was given him, he gave God the honor of truth, and most confidently concluded and believed that what God promised He could also do, although it appeared impossible to his reason; so also here he understands and believes God’s Word and command plainly and simply, as they read according to the letter, and commits the matter to God’s omnipotence and wisdom, which, he knows, has many more modes and ways to fulfil the promise of the Seed from Isaac than he can comprehend with his blind reason...
(bold, italics, underline mine)
While the emphasis of this passage is on the impossibility of sacrificing his son while believing that the promise will be fulfilled through him, the passage make the side point that this command clearly conflicts with common morality. As such, unless we accuse God of commanding immorality. We have to affirm, in some sense, that God's command can occupy a unique sui generis category: being beyond good and evil.