פירוש על כלאים 7:4

Introduction In this mishnah and the two that follow, we learn about what happens if one person sows seed in someone else’s vineyard or someone puts a vine over someone else’s grain. Does this make the grain into kilayim?

One who causes his vine to overhang his fellow’s grain, behold he has caused the grain to be prohibited and he is responsible for it. According to the first opinion, when a vine is hung over grain it causes the grain to become kilayim, even if the grain doesn’t belong to the person who hung up the vine. Since he has ruined someone else’s property, he must pay for the damage he has caused.

Rabbi Yose and Rabbi Shimon say: a person does not prohibit [as kilayim] that which is not his own. Rabbi Yose and Rabbi Shimon hold that a person can’t make kilayim in someone else’s vineyard. This is derived from a midrash on Deuteronomy 22:9, which states, “Don’t seed your vineyard kilayim.” From the word “your” the rabbis learn that this rule applies to one who seeds his own vineyard, and not one who seeds someone else’s vineyard.