[If] one takes olives from the pit, he may dip one [olive] at a time into salt and eat [it without tithing]; [but] if he salted [olives] and placed [them] before himself, he is obligated [to tithe them]. R' Eliezer says: [If one took olives] from a tahor pit, he is obligated [to tithe them]; but [if he takes them] from a tamei [pit], he is exempt [from tithing them], since he returns the surplus.