Kilayim, Chapter Three, Mishnah Three
This mishnah deals with potential problems of kilayim in vegetable fields. Note that I have explained this mishnah according to Albecks commentary.
1) If the point of an angle of a vegetable field overlaps into a field of another vegetable, it is permitted because it looks like the end of his field.
2) His field was sown with a certain vegetable and he wants to plant in it a row of another vegetable:
a) Rabbi Ishmael says: [he may do so] as long as a furrow runs through from one end of the field to the other.
b) Rabbi Akiva says: [as long as] it is six handbreadths long and fully as wide.
c) Rabbi Judah says: [as long as] the width is the full width of a footstep.
Section one: This section is the same as section one of mishnah 2:7. I am copying my commentary here so that you dont have to go back and look at it:
In this case, a point of an angle of a field planted with one type of vegetable enters into, or according to other interpretations, is adjacent to, a field planted with a different type of vegetable. Imagine a triangular field, where one of the corners is next to a square field. Since it looks like the angle is the end of one of the vegetable fields, there is no problem of kilayim here.
Section two: All three sages in this mishnah allow one to plant one row of a different species of vegetable within a field of another species of vegetable. The three sages differ with regard to how long this row has to be.
Rabbi Ishmael says that the row has to run the whole distance of the field, essentially dividing the field in half. This turns the row of a different vegetable into its own field, in which case there is no problem of kilayim.
Rabbi Akiva says that the row need not go the entire distance of the field. His condition is that the row must be six handbreadths wide and as wide below as it is above. That is to say the sides of the furrow dont slant but are rather dug straight down.
Rabbi Judah says that the width need only be as wide as a footstep. In the Talmud this is explained to be one handbreadth. Rabbi Judah agrees with Rabbi Akiva that the furrow need not run the whole length of the field.