Fruit growing in a guarded courtyard, where outsiders may not enter, may be eaten casually, as akhilat arai, only before it has been gathered, since gathering is its gmar melakha. Therefore, one may pick and eat a single grape or a single fig, because each is eaten in one bite and does not count as a completed act of gathering.
However, if one picks two grapes, two figs, or a larger fruit that is not eaten in one bite, such as an apple or a large fig, the picking itself is considered the fruit’s gathering and completes its gmar melakha. In a courtyard, this is the normal way fruit is gathered. Once its gmar melakha is complete, the guarded courtyard fixes it for ma’asrot. Therefore, even casual eating is forbidden until terumot and ma’asrot are separated (MT, Laws of Ma’aser 4:15, 17; Radvaz to MT, Laws of Ma’aser 4:18).
If one climbs a tree in a guarded courtyard and picks a quantity of fruit whose gathering would normally complete its gmar melakha, the fruit nevertheless does not become fixed for ma’asrot while he remains on the tree. Only when he descends to the courtyard floor does the guarded courtyard fix it for ma’asrot. Since eating on the tree is still akhilat arai, he may eat from the fruit there without separating terumot and ma’asrot (MT, Laws of Ma’aser 4:18).
