daf bit: Bechorot 59

[cellio]

A mishna on yesterday's daf explains how tithing livestock is done: put the animals in a shed, make an opening large enough for only one to pass at a time, count them as they come out, and mark every tenth. (We have learned previously that fewer than ten animals are combined with the next year's batch.) In the g'mara on today's daf Raba says: if he has fifteen animals he cannot choose ten and tithe from that; rather he must put all fifteen in, tithe from the first ten, and the remaining five combine next time. This is to prevent him from choosing the ten most-meager animals from which to tithe. (58b mishna, 59b g'mara)