מסכת כלים

פרק כז משנה ח

וכן

And similarly

a cloth

that was (initially) woven (to precisely) three by three (fingerbreadths in size)

and incurred the tumah of a corpse,

and was (then) completed (by weaving) upon it

the entire garment (which shared its tumah from a corpse),

and after that

one thread from its beginning was removed  (meaning the initial piece that was three by three is now smaller than the minimum amount to have the tumah from a corpse)

is tahor from the tumah from a corpse,

but is tamei for contact with something that was tamei from a corpse.

If ne thread from its beginning was removed (after it was tamei from a corpse)

and after that

the entire garment was completed upon it,

it is tahor,

as they said,

(an piece of cloth measuring) three by three (fingerbreadths) that was reduced

is tahor,

but (a piece of cloth measuring) three by three (handbreadths) that was reduced,

even though

it is tahor from midras

it is (still susceptible to becoming) tamei with all (other) forms of tumah.

סדין

A sheet (designed for laying upon)

that was tamei midras,

and was made into a curtain (which, as it is not made to be laid upon, is not susceptible to the tumah of midras)

is tahor from midras

but is tamei for contact with something that was midras.

Rabbi Yosi said,

"And why, with which midras did this come into contact with?

Rather, only if the zav touches it

it it tamei for contact for being in contact with the zav."