Terumos 3:4-5

Terumos 3:4

Two partners can both separate terumah (in 3:3) when they don’t consult. If one of the partners gave permission to a family member or a servant to take terumah, then what that person separates is valid terumah. If he revoked that person’s authorization before they took terumah, then what they take is not terumah. If he revoked authorization after, then what that person takes is terumah. Workmen are not empowered to take terumah for their employers except for those who tread grapes because they can render the wine vat ritually impure in an instant (so we see that their employer trusts and empowers them).

Terumos 3:5

If a person says that the terumah, maaser or terumas maaser of a pile of produce is within that pile, Rabbi Shimon says he has effectively designated these portions. The Sages say that he does not effectively designate these portions unless he specifies that they lie to the north or the south of the pile. Rabbi Eliezer Chisma says that if he says that the terumah of the pile from it is for it, he has effectively designated it. Rabbi Eliezer ben Yaakov says that if one says that a tenth of the maaser is terumas maaser for it, he has effectively designated it.