[Regarding] a block that one set in a row of bricks, [whether] he set it [in the wall] but did not build on it, [or] he built on it but did not set it [into the wall], it is tamei. [But if] he set it [in the wall] and built on it, it is tahor. [Regarding] a mat that one placed over the [ceiling] beams, [whether] he attached it [to the beams] but did not lay plaster over it, [or] he laid plaster over it but did not attach it [to the beams], it is tamei. [But if] he attached it and laid plaster over it, it is tahor. [Regarding] a plate that one attached to a bin, a chest, or a cabinet, [if it was attached] in the way that it receives, it is tamei. [But if it was attached] not in the way that it receives, it is tahor.

[Regarding] a sheet that is [susceptible to becoming] tamei with midras [tumah] and one made it into a curtain, it is impervious to midras [tumah], but it is [susceptible to becoming] tamei with corpse-tumah. From when does it become tahor? Beis Shammai say: From when it is broken. Beis Hillel say: From when it is tied. R’ Akiva says: When it is attached.

A mat in which one placed reed [stalks] along its length is tahor. But the Sages say: Only if [the stalks] are laid similar to the shape of a ki. [If] he placed [the reed stalks] along [the mat’s] width but there are not four handbreadths between one reed and the next, it is tahor. [If] it split in its width, R’ Yehudah rules it tahor. And similarly, if one unties the end knots, it is tahor. [If] it split in its length and three end knots remained of six handbreadths, it is tamei. From when does a mat become susceptible to tumah? From when it is trimmed, and this [represents] the completion of its manufacture.

One who touches the upper beam, the lower beam, the heddles, the reed, the thread which he placed upon purple wool, or a swatch that he does not intend to leave there is tahor. [One who touches] the weft of the fabric, the standing warp, the doubled [material] which he placed upon purple wool, or a swatch that he intends to leave there is tamei. One who touches the wool which is on the distaff [or] on the ashvayah is tahor. One who touches the whorl before he uncovers it is tamei. [One who touches it] after he uncovers it is tahor.