English: A single witness is believed in matters of prohibitions. (As derived from “and he shall slaughter”: the Kohanim eat of the slaughter of the offerings, and the Torah did not require two witnesses at the time of slaughter.)
In the sugya: If two witnesses were required for shechitah validity, the sacrificial system would be unworkable as written. The Torah’s silence on dual witnesses at slaughter, while Kohanim eat from those animals, supports the rule that one witness is believed for issurim.
Type of Learning
Inference from ritual practice — one witness suffices for issurim, unlike capital or monetary cases.
What Is Learned
For issurim (including shechitah validity), one witness is believed. The standard of two witnesses is for punishment and capital/monetary cases, not for this class of prohibition. The sacrificial eating of Kohanim is part of the proof structure.