3,308. A Kohein Who Sells a Cow to a Yisroel, or Vice Versa

Terumos 9:10

The Rambam opines that if a kohein sells his cow to a Yisroel and receives payment for it, he may no longer feed it terumah even if the buyer hasn’t taken possession of it yet. This is because, under Biblical law, exchanging money finalizes a transaction; we will discuss this IY”H in Hilchos Mekach u’Memkar. If a Yisroel sells a cow to a kohein, he may not feed it terumah until he takes possession of it even if he already paid for it.

Terumos 10:1

If a non-kohein eat terumah inadvertently, he must pay it back and add a fifth. This is also the case if he knew it was terumah and was warned not to eat it, but he didn’t know whether or not doing so would render him liable to the penalty of death from Heaven; such a case is also considered inadvertent, so he must pay it back and add a fifth.