daf bit: Zevachim 91

(Today's daf is 92.)

The g'mara on yesterday's daf discusses various types of non-animal offerings. While (olive) oil is brought with (some? all?) meal offerings, the g'mara says that a person can donate oil directly. This is not an offering called for by torah; it's just a donation. (As with most other offerings, a small amount is offered on the altar and the rest goes to the priests.) I was therefore surprised to see a discussion of the minimum donation amount: while you aren't required to donate oil at all, if you do make such a donation it must be at least one log (according to the tannaim) or three logs (according to Rabbi). The tannaim compare the oil donation to a meal-offering (minimum size one log); Rabbi compares it to a wine offering (minimum size three logs). (91b)

(A log is a liquid measure. I don't know the volume.)