Tohoros 8:7-8
Tohoros 8:7
Rabbi Eliezer says that the outsides of vessels that were rendered ritually unclean from liquids convey impurity to liquids but not to foods; Rabbi Yehoshua says that they convey impurity to liquids and also disqualify foods (for use as trumah). Shimon the brother of Azariah says that the outside of vessels do neither of these things but liquids that were rendered impure from the outsides of vessels convey impurity to one and disqualify a second. The result is that the outsides of vessels don’t convey impurity to trumah but the liquids rendered impure by them do.
Tohoros 8:8
Let’s say that a kneading trough was on an incline with dough in the upper part and liquid dripping below. If there are three pieces of dough that altogether make up the volume of an egg, they do not combine, though two pieces do combine. Rabbi Yosi says that even two don’t combine unless they stop the liquid between them. If the liquid is standing, then even pieces the size of mustard seeds combine. Rabbi Dosa says that crumbled food doesn’t combine.