Parashas Vayeira · Passuk 22:2
And He said, “Take, please, your son, your only one, whom you love, Yitzchak, and go to the land of Moriah, and offer him there as a burnt-offering on one of the mountains that I will tell you.”
Torah Temimah points to Sanhedrin 89b.
TT lemma: את בנך.
English: “Your son…” He said to Him, “I have two sons.” He said to him, “Your only one.” He said, “This one is an only son to his mother and that one is an only son to his mother.” He said to him, “Whom you love.” He said, “I love both of them.” He said to him, “Yitzchak.” And why all this? So that his mind would not be confounded by the suddenness of the command.
Derash on the verse (Bavli sugya) — not a formal named middah of the 13. The layered description is read as pedagogical restraint.
God identified Yitzchak only after successive clarifications so that Avraham’s mind would not be overwhelmed by the abruptness of the command.