Kilayim, Chapter 1, Mishnah 2. In the previous mishnah we learned that in a small arugah (garden bed) measuring six tefachim by six tefachim, one may sow five different kinds of seeds. Our mishnah comes to clarify that this permission applies specifically to types of seed that are normally sown in very small quantities, in a plot of this sort; but types that are normally sown over large areas, in a large field, are not included in this permission.
The wording of the mishnah:
"Kol min zera'im ein zor'in ba'arugah" - the word "zera'im" refers here specifically to seeds that are sown over very large areas. These are not sown in an arugah, meaning there is no permission to sow five kinds of them within six tefachim by six tefachim. "Kol min yerakos zor'in ba'arugah" - any type of seed or vegetable that is normally sown in very small quantities may be sown in this arugah.
The examples in the mishnah:
"Chardal va'afunim hashufin" - mustard seed, as well as the small, smooth pea, are considered "min zera'im". Since they are normally sown in very large quantities, there is no permission to sow five different kinds of them in an arugah of six by six tefachim.
"Afunim hagamlonim" - the large variety of pea, is considered "min yarak", and with these one may sow five different kinds in an arugah.
A border that was a tefach high and was diminished:
A further law continues a matter discussed in the previous mishnah: when there is a border a tefach high, one may add more seeds, up to thirteen kinds. The mishnah says: "Gevul shehayah gavoha tefach venitma'et - kasher" - if the border was a tefach high, its proper measure, and afterward was diminished and worn down, it is still valid, "shehayah kasher mitechilaso". Since it was valid at the outset, it is not required to maintain its original size.
The furrow and the water channel:
"Hatelem ve'amas hamayim shehem amukim tefach - zor'im lesochan sheloshah zer'onim" - a furrow or an irrigation channel a tefach deep may be sown with three different kinds of seed: "echad mikan" - on one side of the furrow, "ve'echad mikan" - on the other side, "ve'echad ba'emtza" - and one in the middle, provided that they are at least a tefach and a half apart from one another, which is the measure of absorption mentioned in the previous mishnah, the amount of space within which a plant draws its nourishment.
In summary: in this mishnah we learned that the permission to sow five kinds in an arugah applies to types of vegetables sown in small quantities, and not to types of seed sown over large areas; that a border which was a tefach high and was then diminished remains valid, since it was valid at the outset; and that in a furrow or a water channel a tefach deep one may sow three kinds, one on this side, one on that side and one in the middle, provided that the absorption measure of a tefach and a half is maintained between them.