The following block [immersion] in the case of a person: threads of wool, threads of flax and the ribbons on the heads of girls. Rabbi Judah says: those of wool or of hair do not interpose, because water enters through them.

The matted hair on the heart and on the beard and on a woman's hidden parts; pus outside the eye, hardened pus outside a wound and the plaster over it, dried-up juice, clots of excrement on the body, dough under the finger nails, sweat-crumbs, miry clay, potter's clay, and road-clay. What is meant by 'miry clay’? This means the clay in pits, for it is written: "He lifted me out of the miry pit, the slimy clay" (Psalms 40:3). "Potter's clay" according to its literal sense. Rabbi Yose declares potter's clay clean, but clay for putty unclean. And "road-clay." These become like road-side pegs in these [kinds of clay] one may not immerse oneself nor immerse [other things] with them; But in all other clay one may immerse when it is wet. One may not immerse oneself with dust [still] on one's feet. One may not immerse a kettle with soot [on it] unless he scraped it.

The following do not block: the matted hair of the head and of the armpits and of a man's hidden parts. Rabbi Eliezer says: it is the same with a man or a woman: if it is something which one finds annoying, it blocks; but if it is something which one does not find annoying, it does not interpose.

In the case of vessels the following block: pitch and myrrh; In the case of glass vessels, whether inside or outside; On a table or on a board or on a couch; On those that are [usually] kept clean they block; On those that are allowed to remain dirty they do not block. They block in the case of beds belonging to householders, but they do not block on beds belonging to a poor person. They block on the saddle of a house-holder, but they do not block on the saddle of a dealer in water-skins. They block in the case of a pack-saddle. Rabban Shimon ben Gamaliel says: [only if the stain is as big] as an Italian issar.

On clothing: if on one side [only] they do not block. But [if found] on two sides they do block. Rabbi Judah says in the name of Rabbi Ishmael: on one side also. Rabbi Yose says: in the case of builders they block if on one side, but in the case of the ditch-digger only if on both sides.

They do not block in the case of aprons belonging to workers in pitch, potters, or trimmers of trees. Rabbi Judah says: the same applies also to summer fruit-driers. This is the general rule: if it is something which one cares enough [to remove], it blocks; but if it is something which one does not care enough [to remove], it does not block.