Parashas Behar · Aliyah 1 · Passuk 25:09
Chabad.org — English translation + Rashi
Torah Temimah cites Rosh Hashanah 34b.
English: “In the seventh month.” Why is this said? To teach that all teruah-blasts of the seventh month are like one another; and from where do we transfer what is said of one to the other? The verse says “seventh / seventh” for a Gezeirah shavah.
Gezeirah shavah (Bavli Rosh Hashanah).
All teruah-blasts of the seventh month share the same laws; the measures of tekiah and teruah are equated by Gezeirah shavah.