פירוש על שבת 17:3

קנה של זיתים – a reed that is made to check the olives that are in the pit or vat where olives are packed until they form a viscid mass, if their oil was gathered in them and that they were worthy of the olive press.

Introduction This mishnah discusses a “reed for olives.” This is a vessel used in the process of making olive oil. They would put the olives in a large container so that they would heat up, start to soften and the juice would flow out. The container would be flipped over by using the “reed for olives.” When they flipped the container they would check the reed to see if it was moist. If it was they would know that the olives were soft and that they could begin to press them. Our mishnah teaches two laws with regard to this reed: its susceptibility to impurity and whether it may be carried on Shabbat. Both laws depend on whether or not the reed is considered to be a “vessel.”

אם יש קשר בראשו – a sort of stopper that is in the reed is susceptible for ritual impurity because it is stopped up at the knot, it is left over in it from the oil that flows from the olives and he checks it if it arrived to stopping and it is a receptacle for him.

A reed for olives, if it has a knot on its top, is susceptible to impurity; if not, it is not susceptible to impurity. Sometimes they would make a small knot on top of the reed. This knot would serve as a small receptacle for the olive oil and it would make it easier to check if the olives were ready. If the reed has such a knot then it is susceptible to impurity and if not, then it is not susceptible. Wooden vessels are generally only susceptible to impurity if they have a receptacle.

ואם לאו – if it has no knot, even though it is hollowed, he did not hollow it out to receive anything. Therefore, he has a flat wooden implement (see Talmud Shabbat 123b) and is not susceptible for ritual impurity.

In both cases it may be handled on Shabbat. Since this is a vessel, it is permitted to carry it on Shabbat either to use it to do something permitted, or to move it because she needs to use the space it occupies. In other words, with regard to receiving impurity, this is not a vessel unless it has a knot, but when it comes to Shabbat, it is considered a vessel with or without the knot. Had it not been considered a vessel, it would have been prohibited to carry it on Shabbat for any reason.

בין כך ובין כך ניטל בשבת – for it is an implement and it is used to turn over the olives.