Kilayim, Chapter Seven, Mishnah Three
This mishnah continues to deal with situations in which it is prohibited to plant seeds, but if the seeds are planted there, they do not become kilayim.
The following are forbidden, but they do not prohibit [the seed sown there]:
1) The remainder of a [legally inadequate] empty patch (karahat) of a vineyard.
2) The remainder of a [legally inadequate] mehol of a vineyard.
3) The remainder of a [legally inadequate] aris-gap.
4) The [ground under the] remainder of papyrus-ropes [of a trellis].
5) But [the ground] beneath a vine, and within the place left to work a vine, and the [ground within] four cubits of a vineyard, these do prohibit the [seed sown there].
Section one: In mishnah 4:1 we learned about the empty patch in the vineyard, and that the patch must be 16 cubits before one can sow seeds there. If the patch is not large enough then it is forbidden to plant in the patch, even if he leaves four cubits of space to work the vineyard. However, since he did leave room to work the vineyard, the seed is not prohibited as kilayim.
Section two: The mehol is the empty space between the vineyard and a fence. If this space is 12 cubits then it is permitted to sow seeds there. It is forbidden to sow seeds if there are less than 12 cubits, but if he leaves four cubits space to work the vineyard, then the seeds are not kilayim.
Section three: We learned about sowing seeds in the gap of an aris (a trellis) in 6:6there must be a gap of more than eight cubits between the sections for it to be permitted to sow seeds there. It is forbidden to sow seeds if there are 8 cubits or less, but if he leaves six handbreadths to work the individual vines that are left, then the seeds are not kilayim.
Section four: We learned about these ropes in 6:3. These ropes were used to extend the vine to help keep it up. It was forbidden to plant underneath the ropes, but if one does the seeds are not prohibited.
Section five: In contrast, in these situations if seeds are planted they are prohibited as kilayim. There are three such situations: 1) planting directly underneath the vines; 2) planting within the six handbreadths which one must leave to work an individual vine; 3) planting an area of four cubits within a vineyard.