Chabad.org — English translation + Rashi
Torah Temimah points to Menachos 58a.
E-Daf.com — Menachos 58a
HebrewBooks / Shas PDF
English: Might the community bring a free-will gift of leaven and honey as they bring their obligatory [forms]? The verse says “you shall offer them” — them, and not a free-will gift of the same kind.
Miyut of communal nedavah of se’or/devash — only the obligatory two loaves and bikkurim are permitted.
The community’s leaven/honey forms are only the obligatory two loaves and bikkurim, not free-will parallels. The verse’s “you shall offer them” is read as excluding any additional free-will offering of the same kind.