3,453. A Learned Messenger

Hilchos Maaser 10:8

Let’s say that an unlearned person gives a meah (a denomination of currency) to a learned person with instructions to buy him a bunch of vegetables or a cake. In such a case, the learned person may buy him untithed produce without any obligation to tithe it. If the learned messenger made change for the meah, then he must tithe what he buys. If the learned person explicitly says that he’s buying bunch of vegetables A for his friend and bunch of vegetables B for himself, then he must tithe what he bought for himself and not what he bought for his friend. If these two bunches get mixed up – even one of the learned person’s with 100 of the unlearned person’s, he must rectify the whole thing as demai (doubtfully tithed produce). After doing this he can give the produce to the friend who sent him to buy it.

Hilchos Maaser 10:9

Let’s say that five people tell one messenger to go get them five bunches of vegetables and the messenger brings each one his own bunch. In such a case, the learned among them need only tithe their own bunches. If the messengers brought all five bunches together, the learned recipients must take tithes for all of them.