Chabad.org — English translation + Rashi
Torah Temimah points to Menachos 92a.
E-Daf.com — Menachos 92a
HebrewBooks / Shas PDF
English: “On the head of the bull” — why say “the bull”? To teach: a bull requires semichah, and the goats of idolatry do not require semichah.
Miyut of se’irei avodah zarah from semichah — communal idolatry-goats are excluded from the semichah requirement of this bull.
The verse’s specification of “the bull” teaches that semichah is required for the par he’elam davar but is not required for the se’irei avodah zarah. The miyut keeps the two communal offerings distinct in their procedural details even though both arise from national-level error.