3,258. Calling Terumah Maaser or Vice Versa

Terumos 4:15

If a non-Jew takes terumah from his own produce, it’s not terumah under Biblical law because he is not obligated in terumah. The Sages declared it terumah under Rabbinic law out of concern that a Jew might claim that it belongs to a non-Jew in order to avoid taking terumah. A non-Jew who takes terumah is interviewed as to his motivation. If he says that he did so in order to make his produce like that of a Jew, the terumah is given to a kohein; if not, it is locked away because perhaps his intention was to consecrate it. This is only the case in Israel; the Sages didn’t make an enactment regarding a non-Jew who takes terumah in other lands. In such cases, he is simply told that he has no such obligation and the produce isn’t terumah at all.

Terumos 4:16

If someone separates produce and he intends to call it terumah, but he accidentally calls it maaser, or he intends to call it maaser, but he accidentally calls it terumah, his statement is ineffective because his words must match his intention. If one separates terumah mentally without actually saying anything, what he separated is valid terumah as per Numbers 18:27: “It will be considered for you your terumah,” i.e., it can be rendered terumah through thought alone.