Makhshirin, Chapter Six, Mishnah One
1) One who carries his produce up to the roof because of maggots, and dew came down upon it, it does not come under the law of if water be put;
a) But if he intended for this to happen, it does come under the law of if water be put.
2) If a deaf-mute, or a person not of sound senses, or a minor carried it up, although he expected that dew should come down upon it, it does not come under the law of if water be put, because with these the act alone counts, but not the intention.
Section one: This person carries his produce up to the roof because he hopes that the maggots that got into his produce will go out there. He doesn’t intend for the produce to become wet. Therefore, the dew that comes down on it does cause it to be susceptible to impurity.
However, if he intentionally brings it up to the roof so that it will get wet, it does cause susceptibility.
Section two: This section is one of the clearest statements with regard to intent found in the entire Mishnah. These three categories of people are understood as not having the mental awareness sufficient for their action to have intent (we have seen this many times throughout the Mishnah). Therefore, we judge their actions by themselves, without resort to assumptions of intent. Since bringing produce up to the roof is not sufficient for it to become susceptible to impurity, the produce remain unsusceptible.