Bechoros 4:10-5:1

Bechoros 4:10

A person who is suspected of dealing in sabbatical year produce is not suspected of selling tithes as secular produce, nor is one who is suspected regarding tithes suspected of dealing in sabbatical produce. One who is suspected of either of these is also suspected regarding ritual purity (which involves a lot of rabbinic prohibitions), though one who is suspected regarding ritual purity is not necessarily suspected regarding tithes or sabbatical year produce (which are Biblical prohibitions). The general principle is that a person who is suspected in a certain matter may not render judgment nor give testimony in that matter.

Bechoros 5:1

All consecrated animals that have been rendered unfit may be sold and slaughtered in the market, and weighed by the pound, except for a firstborn animal and a tithe animal. This is because the proceeds of their sale goes to their owners, as opposed to other disqualified consecrated animals whose proceeds go to the Temple (i.e., an individual profiting from a disqualified consecrated animal doesn’t justify the disgrace of selling them publicly). However, a portion of meat from a firstborn animal may be weighed against a portion of secular meat whose weight is known.