TT #14 · Parashas Vayeishev · Passuk 37:21
And Reuven heard it, and delivered him out of their hand; and said: Let us not take his life.
Torah Temimah points to Makkos 10a.
Rabbi Tanchum bar Chanilai said: Why did Reuven merit to be listed first among the cities of refuge? Because he was the first to begin an act of rescue, as it is said: “And Reuven heard and delivered him from their hand.”
Derash on the verse (Bavli sugya) — not a formal named middah of the 13. The derashah connects Reuven’s first act of rescue with the first placement of his city among the cities of refuge.
Reuven’s rescue of Yosef is remembered through the first-listed city of refuge in his territory, because he was the first to begin the rescue.