829. Separating Tithes on Shabbos

Shabbos 23:15

If a person separated terumah and tithes on Shabbos or yom tov without intention to violate the law, he may eat the produce that he rendered fit. If he intentionally violated the law, he may not eat the produce until after Shabbos, though the act of separating terumah and tithes remains effective. Similarly, if a person consecrated, appraised or set aside property on Shabbos, the act is effective whether or not he intended to violate the law in doing so. This also applies on yom tov. Similarly, a business transaction enacted on Shabbos is effective. During the twilight period on Friday, we may separate tithes from doubtfully-tithed produce (demai) but not from definitely-untithed produce.

Shabbos 23:16

If a person designates some demai as terumas maaser (the portion given to kohanim by Leviim) or as the tithe for the poor, he should not deliver them to the recipients on Shabbos. This is so even if the location from which they would be taken was designated before Shabbos and they were placed in a specific location. However, if a kohein or a needy person regularly dines at this person’s home, he may come and eat these things as long as the host informs the kohein that he is being fed from terumas maaser and the needy person that he being fed from tithe for the poor.