All mats are [liable to become] impure by “corpse” impurity, the words of Rabbi Dosa. But the Sages say: “[Also by] “midras” impurity. Rabbi Dosa and the Sages disagree with regards to the susceptibility of mats to midras impurity. Midras impurity is a type of impurity which is received by a zav sitting or lying down on an object. Only things that are typically sat on or lied down upon can receive this type of impurity. According to Rabbi Dosa, mats can receive corpse impurity by coming into contact with a dead body, or a part thereof. However, since the mats under discussion are not used for sitting or for lying down, they cannot receive midras impurity. The Sages hold that they can, since they are occasionally used for such a purpose.
All network is unsusceptible to impurity except a [network] girdle, the words of Rabbi Dosa. But the Sages say: “They are all liable to uncleanness, except those used by wool dealers [for carrying raw wool].” Network, things made of nets (not computer networks, which I suppose cannot receive impurity), are not considered by Rabbi Dosa to be clothing and therefore they cannot receive impurity. As we learned on several occasions, only things that are formed vessels or clothing can receive impurity. Since network is not really clothing, it cannot receive impurity. The only exception to this rule about things made of nets is a type of girdle which is a piece of clothing and therefore can be made impure. The Sages disagree. They hold that network is considered clothing. The only exception is a bag used by wool dealers to hold wool. Since this is definitely not clothing it cannot be made impure.
Questions for Further Thought:
• We have now learned several disputes between Rabbi Dosa and the Sages. Do you seen any consistency to their opinions?
• Mishnah four: What modern items might be similar to the mats and network under discussion in this mishnah?