Rabbi Joshua said: if a menstruant sat in a bed with a clean woman, [even] the cap on her head contracts midras uncleanness. And if she sat in a boat, the vessels on the top of the mast [also] contract midras uncleanness. If there was [on the boat] a tub full of clothes: If their weight was heavy, they become unclean, But if their weight was light, they remain clean. If a zav knocked against a balcony and thereby caused a loaf of terumah to fall down, it remains clean.

If he knocked against a door, doorbolt, lock, oar, mill basket, or against a weak tree, or weak branch of a strong tree, or against an Egyptian ladder unsecured by nails, or against a bridge, beam or door, not made secure with clay, they become unclean. [If he knocked] against a chest, box or cupboard, they become unclean. Rabbi Nehemiah and Rabbi Shimon declare them clean in these cases.

A zav who lays across five benches, or five money-belts: If lengthwise, he [makes them] unclean; But breadthwise, they are clean. If he slept [on them], and it was doubful that he had turned over onto them, they are unclean. If he was lying on six seats, with two hands on two [seats], two feet on another two, his head on one, with his body on another one, only that one on which his body lay is rendered unclean. If [a zav] stood on two seats: Rabbi Shimon says: if these were distant one from the other, they remain clean.

Ten cloaks one on top of the other, if he sat on the uppermost one, all are unclean. A zav who was on one scale of a balance and in the other scale opposite there were objects fit to sit or lie upon: If the zav pushed them up, they are clean. But if they pushed him up, they are unclean. Rabbi Shimon says: if there was one object it becomes unclean, but if there were many they remain clean, since none of them had borne the greater part [of the zav's weight].

If a zav [sat] in one scale of the balance, while food and liquids were in the other scale, [the latter become] unclean. In the case of a corpse, everything remains clean except for a man. This is [an example of] the greater stringency applying to a zav than to a corpse; and there is a greater stringency in the case of a corpse than a zav. For whereas the zav defiles all objects on which he sits or lies upon, so that these likewise convey uncleanness to people and garments, and he conveys to what is above him madaf uncleanness, so that these in turn defile food and liquids. Whereas in the case of a corpse no such uncleanness is conveyed. Greater stringency is also found in the case of a corpse, since it can convey uncleanness by overshadowing, and it defiles seven days’ defilement, whereas in the case of a zav no such uncleanness is conveyed.

If he sat on a bed and there were four cloaks under the four legs of the bed, all become unclean, since the bed cannot stand on three legs; But Rabbi Shimon declares them clean. If he rode on a beast and there were four cloaks under the legs of the beast, they are clean, since the beast can stand upon three legs. If there was one cloak under its two forelegs or its two hindlegs, or under a foreleg and a hindleg, it becomes unclean. Rabbi Yose says: a horse conveys uncleanness through its hindlegs and a donkey through its forelegs, since a horse leans upon its hindlegs and a donkey upon its forelegs. If he sat on a beam of an olive-press, the vessels in the olive-press receptacle are unclean. [If he sat] on a clothing press, the garments beneath it are clean. Rabbi Nehemiah declares them unclean.