[If] someone was passing through [his] vineyard and seeds fell from him, or [seeds] were released together with the dung or with the water, [or if] someone was sowing and the wind blew [seed] behind him — it is permitted. [If] wind blew [seed] in front of him, R’ Akiva says: If [it grows] grasses he must turn it; if the grains have begun to ripen, he must shake the grains out of the ears; if it has produced completed grain, it must be burned.