Makhshirin, Chapter Three, Mishnah Two
1) A jar full of produce which was put into liquids, or a jar full of liquids was put into produce and [the produce] absorbed, all [the produce] which absorbed comes under the law of if water be put.
2) Concerning what liquids were they speaking? Water, wine and vinegar; but all the other liquids do not cause susceptibility to uncleanness.
3) Rabbi Nehemiah says pulse is insusceptible, because pulse does not absorb [liquids].
Section one: The jar is made of earthenware which will easily absorb water. It doesn’t matter whether the jar has liquids and it is put into the produce or the jar has produce and it is put into liquidsin all of these cases the produce that has absorbed any liquid is susceptible to impurity. This is true even of pulse (mostly beans) which is less absorbent than other produce such as grain.
Section two: This halakhah is limited to two of the 7 liquids that cause susceptibility: water and wine (vinegar is made of wine). The other liquids (we will see the full list in 6:4dew, oil, blood, milk and honey are the other five) are thicker and will not be as easily absorbed. Therefore, they won’t cause the produce to be susceptible.
Section three: Rabbi Nehemiah says that pulse put in such a jar is not susceptible to impurity because it is less likely to absorb the liquid. In other words, whereas the previous opinion only limited the thicker, less absorbable liquids, Rabbi Nehemiah adds that the thicker less absorbent produce doesn’t become susceptible to impurity.