EXTRA · Parashas Vayeishev · Passuk 38:29 · not a Torah Temimah citation on this passuk
But just then it drew back its hand, and out came its brother; and she said, “What a breachgbreach Heb. pereṣ, connected with “Perez.” you have made for yourself!” So he was named Perez.
Classical source (EXTRA side-ring): Bereshis Rabbah 85:14.
Sefaria — Bereshis Rabbah 85:14
English: “What a breach you have breached for yourself” — this is Moshiach, as it is said: “The breaker goes up before them.”
Derash on the verse (Bereshis Rabbah) — not a formal named middah of the 13. Name and birth-act are projected onto future redemption.
Peretz is the breach through which the Davidic and messianic line will emerge.