[A laborer] who is working with levasim figs may not eat benos sheva figs; [if he is working] with benos sheva figs, he may not eat levasim figs, but he may restrain himself [from eating] until he reaches the place of the superior [figs], and eat [those].  If one barters [produce] with his friend, [and] this person [receives produce that had been designated] for eating and this [other] person [also receives produce that had been designated] for eating; [or] this person [receives produce that had been designated] for drying and this [other] person [also receives produce that had been designated] for drying; [or] this person [receives produce that had been designated] for eating and this [other] person [receives produce that had been designated] for drying, [each one is] obligated [to tithe the produce he receives]. R' Yehudah says: The one who bartered [for produce that had been designated] for eating is obligated [to tithe it], but [the one who bartered for produce that had been designated] for drying is exempt [from tithing it].