Parashas Chayei Sarah · Passuk 23:10
Now Ephron was sitting among the children of Cheis; and Ephron the Chittite answered Avraham in the hearing of the children of Cheis, of all who entered the gate of his city, saying:
Rashi on Bereishis 23:10 (classical source on this passuk; not listed as a numbered Torah Temimah unit here).
Lemma / focus: ועפרון ישב.
English: It is written defectively [without a vav]: that very day they appointed him an officer over them; because of the importance of Avraham, who needed him, he rose to greatness.
Derash on the verse (Rashi / midrashic spelling) — not a formal named middah of the 13: the missing letter is taken as a signal of a new appointment on that day.
On the day Avraham sought the cave, Ephron was newly appointed an officer among the children of Cheis; his rise is linked to Avraham’s need of him.