Shabbat 11 - Friday afternoon
On Friday afternoon close to sundown, a tailor should not go out into the street with his needle, lest he forget that has it, and come to carry it four steps in the street, when it is already dark, which would be a Shabbat violation. Similarly, a scribe should not go out with his pen. Even though a pen is much larger than a needle, he still might forget that he is carrying it, and this applies even to objects larger than a needle.
Why are the above rules true? A tailor usually carries his needle pinned to his clothing; this is an uncommon manner of carrying, and as such it is not prohibited by the Torah, but only by the decree of the Sages. A further precaution of not carrying it while it is still Friday would constitute a decree to protect another decree, and that is usually not done!? We have to admit that he is carrying it in his hand.
But we learned a clear rule, that a tailor should not go out of Friday afternoon with a needle pinned to his garment! - That is talking on Shabbat itself. But we learned yet another rule, that he should not go out with a needle pinned to his garment on Friday afternoon!? - We have to admit that this rule is not universal, but that it is only the opinion of Rabbi Yehudah, who says that for a craftsman the way of carrying common in his profession is in fact prohibited by the Torah on Shabbat.
Indeed, we learned the following rule in the name of Rabbi Yehudah: "A carpenter may not go out with his ruler behind his ear, nor a money-changer with a dinar behind his ear" - which proves our point.
Art: Quiringh Gerritsz. van Brekelenkam - The Tailor's Workshop