Kelim, Chapter Twenty-One, Mishnah Three
1) One who touches the handle of a saw at either end becomes unclean;
2) [If he touched] its string, cord, cross-piece or side-pieces, a carpenter’s vice, or the bow-handle of a bow-drill, he remains clean.
a) Rabbi Judah says: so too he who touches the frame of a large saw remains clean.
3) One who touches the bow-string or the bow, even though it was stretched, he remains clean.
4) A mole-trap is clean.
a) Rabbi Judah says: when it is stretched, the separate parts are [regarded as] connected.
Section one: The handles of a two-handled saw are both considered to be part of the saw. Therefore, one who touches either of them is unclean.
Section two: The string or cord run from one handle of the saw to the other to keep them attached. A cross-piece is a piece of wood connecting the handles on a saw. The side-pieces support the handles of a saw. The carpenter’s vice is made of two boards, between which the carpenter places bent pieces of wood to straighten them. If one touches any of these things, he remains clean. Rabbi Judah adds that the same is true with regard to the frame of a large saw.
Section three: The different parts of the bow (as in bow and arrow) are not considered to be connected to one another. Therefore, if one touches the bow-string when the bow is unclean or the bow when the arrow is unclean, he is not unclean. This is true even if the arrow is taut in the bow.
Section four: The various parts of a mole trap are not considered to be connected one to the other. If one is unclean, and a person touches the other part, he is still clean.
Rabbi Judah says that when the mole-trap is stretched, ready to trap the mole, the separate parts are considered to be connected. They are considered unconnected only when the trap mechanism is relaxed.