Parashas Vayeira · Passuk 18:20
And Hashem said, “The outcry of Sedom and Amorah is great, and their sin is very heavy.”
Torah Temimah points to Yerushalmi Bava Metzia 4:2.
TT lemma: כי רבה.
Sefaria — Yerushalmi Bava Metzia
English: “For it is great.” Concerning Sedom it is written “the outcry of Sedom and Amorah is great,” and concerning the generation of the Flood it is written “And Hashem saw that the wickedness of man was great.” This teaches that the deeds of the one were like the deeds of the other.
Derash on the verse (Yerushalmi) — not a formal named middah of the 13. Parallel wording links two generations of corruption.
The sin of Sedom was of the same character and magnitude as the sin of the generation of the Flood; both are described with the word “rabbah.”