Demai

Demai (Mishnaic Hebrew: דמאי) is a Halakhic term meaning "dubious," referring to agricultural produce, the owner of which was not trusted with regard to the correct separation of the tithes assigned to the Levites, although the terumah (the part designated unto priests) was believed to have been separated from such fruits. In such "dubious" cases, all that was necessary was to separate the one-tenth portion due to the priests from the First Tithe given to the Levites, being the 1/100th part of the whole. The Second Tithe is also removed (redeemed) from the fruit in such cases of doubt.

The tribe of Levi, having been excluded from participating in the division of the land, obtained as compensation a share in its produce (Numbers 18:24). As the tribe included two elements, priests and Levites, the compensation was given in two forms: "terumah" (heave-offering) and "ma'aser" (tithes) for the Levites; and the latter gave the tenth part of the tithe to the priests as "terumat ma'aser" (heave-offering of the tithe: Numbers 18:26). In addition, a second tithe had to be separated from the produce in the first, second, fourth, and fifth years of the year-week. This tithe had to be taken to Jerusalem and consumed there, in accordance with certain regulations; while in the third and sixth years it was given to the poor. In the former case it was called "ma'aser sheni" (second tithe); in the latter "ma'asar 'ani" (the tithe for the poor). The produce of the seventh year was free from all these dues.

There are several opinions concerning the word's etymology. According to Maimonides and Rabbi Obadiah ben Abraham, the word originates from a contraction of the two Aramaic words דא מאי meaning "doubtful" (literally, "what is this?"). Another possibility is that the word originates from a corruption of the Hebrew word דמע, "things holy", in this case referring to something which may still contain the elements of "things holy".

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