A bolster and a cushion of leather it is necessary that the water enter inside them. A round cushion or a ball or a bootmaker's last or an amulet or a phylactery, it is not necessary that the water enter inside them. This is the general rule: any article the filling of which is not usually taken out and put in may be immersed unopened.

The following do not require that the water shall enter inside them:Knots [in the clothes] of a poor man, or in tassels, or in the thong of a sandal, or in a head-tefillin if it is fastened tightly, or in an arm-tefillin if it does not move up or down, or in the handles of a water-skin, or in the handles of a wallet.

The following require that water shall enter inside them:The knot in an undergarment which is tied to the shoulder. The hem of a sheet must be stretched out. And the knot of head tefillin if it is not fastened tightly, Or of the arm-tefillin if it moves up and down. And the laces of a sandal. Clothes which are immersed when they have just been washed must be kept immersed until they bubble up; But if they are immersed when already dry, they must be kept immersed until they throw up bubbles and then cease to bubble up.

Any handles of vessels which are too long and which will be cut short, need only be immersed up to the point of their proper measure. Rabbi Judah says: [they are unclean] until the whole of them is immersed. The chain of a large bucket, to the length of four handbreadths, and a small bucket, to the length of ten handbreadths, and they need only be immersed up to the point of their proper measure. Rabbi Tarfon says: it is not clean unless the whole of the chain-ring is immersed. The rope bound to a basket is not counted as a connection unless it has been sewn on.

Bet Shammai say: hot water may not be immersed in cold, or cold in hot, foul in fresh or fresh in foul. But Bet Hillel say: it may be immersed. A vessel full of liquids which one immersed, it is as if it has not been immersed. If it was full of urine, this is reckoned as water. If it contained hatat waters, [it is unclean] unless the water [of the mikveh which enters the vessel] exceeds the hatat waters. Rabbi Yose says: even if a vessel with the capacity of a kor contains but a quarter-log, it is as if it had not been immersed.

All foods combine together to make up the half of a half-loaf which makes the body unfit. All liquids combine together to make up the quarter-log which makes the body unfit. This is more of a stringency in the case of one who drinks unclean liquids than in the case of the mikveh, for in this case they have made all other liquids like water.

If one ate unclean foods or drank unclean liquids and then he immersed and then vomited them up, they are still unclean because they did not become clean in the body. If one drank unclean water and immersed and then vomited it up, it is clean because it became clean in the body. If one swallowed a clean ring and then went into the tent of a corpse, if he sprinkled himself once and twice and immersed himself and then vomited it up, behold, it remains as it was before. If one swallowed an unclean ring, he may immerse himself and eat terumah. If he vomited it up, it is unclean and it renders him unclean. If an arrow was stuck into a man, it blocks so long as it is visible. But if it is not visible, he may immerse himself and eat terumah.