They may not give terumah from pure [produce] for impure [produce], but if they did give, the terumah is terumah. In truth they said: If a cake of pressed figs had become partly defiled, one may give terumah from the clean part for that part which had become defiled. The same applies to a bunch of vegetables, or a stack of grain. If there were two cakes [of figs], two bunches [of vegetables], two stacks [of grain], one pure and one impure, one should not give terumah from one for the other. Rabbi Eliezer says: one can give terumah from that which is pure for that which is impure.

They may not give terumah from impure [produce] for that which is pure. If he did give: If unwittingly, the terumah is valid; If intentionally he has done nothing. So too, if a Levite had [unclean] tithe [from which terumah] had not been given, and he gave terumah from this, if unwittingly, the terumah is valid, if intentionally he has done nothing. Rabbi Judah says: if he knew of it at the outset, even if done in error, he has done nothing.

One who immerses [unclean] vessels on Shabbat: If unwittingly, he may use them. But if intentionally, he may not use them. One who separates tithes, or cooks on Shabbat: If unwittingly, he may eat it. But if intentionally, he may not eat it. One who plants on Shabbat: If unwittingly, he may keep the tree. But if intentionally, he must uproot it. But if during the sabbatical year, whether [it was planted] unwittingly or intentionally he must uproot it.

They may not give terumah from one kind for another kind, and if he did give, the terumah is not terumah. All kinds of wheat count as one. All kinds of fresh figs, dried figs and fig cakes count as one, and he may take terumah from one for the other. Wherever there is a priest, one must give terumah from the very best, and where there is no priest, one must give terumah from that which lasts longest. Rabbi Judah says: he should always give only from the very best.

They should give terumah of a whole small onion, and not of half of a large onion. Rabbi Judah says: not so, rather half of a large onion. So too, Rabbi Judah says: they give terumah from town onions for those from the village, but not from village onions for those from the town, since these are the food of its principal citizens.

They may give terumah from olives [to be used] for oil for those to be preserved, but not from olives due to be preserved for olives [to be used] for oil. [They may give] from unboiled wine for boiled wine, but not from boiled wine for unboiled wine. This is the general rule: any two things which together are kilayim (mixed species) he should not give terumah from one for the other, even if one is superior and the other inferior. But if they are not kilayim, then one may give terumah from the superior for that which is inferior, but not from the inferior for that which is superior. If one does give terumah from the inferior for that which is superior, his terumah is terumah, except for zunin given for wheat, since these (zunin) are not food. Cucumbers and melon count are one kind. Rabbi Judah says: two kinds.