Chabad.org — English translation + Rashi
Torah Temimah points to Toras Kohanim (Sifra), Vayikra Dibbura DeChovah, on 4:27 (me-am ha-aretz — even if several act) (unit 5; single primary locus per emergency Core plan).
Sefaria — Sifra / Toras Kohanim, Vayikra Dibbura DeChovah
English: “From the people of the land” — might one think, since “one soul” is written, only a single person who acted is liable and not two or three who acted? The verse says “from the people of the land” — even if they are many.
Group members each liable when each acts — when several individuals each perform the prohibited act, each brings his own chatas.
If two or three people each independently perform the same prohibited act, each is liable for his own private chatas. The verse’s language does not limit liability to a single solitary sinner; once each has performed the complete act, each is responsible for his own offering.