"do not return to take it": to exclude (from shikchah) the heads of rows. From here they ruled: The heads of rows — the sheaf adjoining it indicates their status (vis-à-vis shikchah). And if he forgot a sheaf that he had taken hold of to take to the city, they agree that this is not shikchah. If a sheaf were forgotten by the owner, but not by the workers, or vice versa; or if the poor stood before it or covered it with straw, it is not shikchah.
"do not return to take it": all as one. And what capacity must it have (to render it subject to shikchah)? The sages estimated: less than two sa'ah. From here they ruled: If they forgot a sheaf of two sa'ah, this is not shikchah. (If they forgot), two sheaves containing two sa'ah between them, R. Gamliel said: They are the owner's; the sages say they belong to the poor. R. Gamliel asked them: If there are more sheaves, is the power of the owner increased or decreased? They: It is increased. R. Gamliel: If they forgot one sheaf containing two sa'ah, it is not shikchah, how much more so, if they forgot two sheaves containing two sa'ah! They: No, this is so for one sa'ah, which is like a pile. Would you say the same for two, which are like bunches!