Maaser Sheni 4:11-12

Ma’aser Sheini 4:11

If one finds a container marked with the letter kuf, the contents are assumed to be an offering (korban); mem, it is assumed to be tithe (maaser); daled, it is assumed to be doubtfully tithed (demai); tes, it is assumed to be untithed (tevel); taf, the portion for kohanim (terumah). They started using these initials when the secular government prohibited observing these mitzvos. Rabbi Yosi said that all these initials are assumed to stand for people’s names. Not only that, even if a container had the actual word “terumah” written on it, we would assume the contents are secular – that it previously held terumah but that is no longer the case.

Ma’aser Sheini 4:12

If a person tells his son that second tithe is to be found in corner A but the son found produce in corner B, it is secular. If he says there is a maneh (100 zuz) of second tithe and the son found 200 zuz there, the additional money is secular. If he said there is 200 zuz and the son found 100 zuz there, it is all tithe money.