One of the activities forbidden on the Sabbath is carrying items in the public domain. One is, though, permitted to wear jewelry or any item which is required, such as a bandage on a wound or cotton in the ear to absorb ear wax. Therefore the early sages (Tanaaim) permitted a woman to go out with cotton in her ear, cotton in her sandal to ease foot pains, or feminine hygiene products during her period. The scholars qualified this permission and ruled that a woman may go outside with cotton in her ear only if it is tied to her ear, for fear that the cotton will fall and she will have to pick it up, effectively carrying it in the public domain. Similarly, the scholars ruled that the cotton in her sandal must be tied to her sandal for the same reason. One of the scholars, Rami son of Hama, concluded that even the feminine hygiene product must be tied between her thighs. A different scholar, Rava, argued that the feminine hygiene product does not need to be tied between her thighs because if it fell, the woman would not want to pick it up and put it back where it came from; it would be soiled and one does not put a soiled feminine hygiene product back where it came from if it fell out. One of the scholars, Rabbi Jeremiah, asked about a feminine hygiene product which has an applicator, like a tampon. What are the issues under debate? On one hand, since it has an applicator there is a fear the woman will return it to its place as it is not disgusting to do so, and we ought to require the tampon be tied between her thighs. On the other hand, even if it does have a special applicator, the padding itself is disgusting and no woman would put it back after it falls out. Answer: One may go out with feminine hygiene products on the Sabbath, even if they have special applicators.
One of the scholars, Rabbi Yochanan, customarily went out on the Sabbath with cotton in his ear and not tied to it, in contradiction with the opinion of most sages. The scholars asked: Was it not ruled in Halacha that one is forbidden to go out with cotton in one’s ear if it is not tied to the ear? How did Rabbi Yochanan act in contradiction with the law? Answer: If the cotton is stuck firmly in the ear one may go out with it without tying it, as Rabbi Yochanan did. The requirement to tie the cotton is when the cotton is not firmly stuffed in the ear.
(Babylonian Talmud, Tractate Shabbat 65a)