Question:

Is there an actual prohibition or restriction against wearing Tzitzis [i.e. the Tallis Katan] on one’s bare chest and skin? I have always been told not to do so and to always wear it over an undershirt although sometimes at night in the summer it is too hot for me to wear an undershirt and I really need to breathe my skin, so can I wear it without an undershirt?

Answer:

There is no real prohibition against wearing a Tallis Katan on one’s actual skin. Nevertheless, the Arizal was accustomed to wear the Tallis Katan over the undershirt, and following in his footsteps, it has likewise become the widespread custom amongst Chassidim to wear it only over the undershirt. Nonetheless, this is not an obligation and hence when one feels it necessary, he may wear it over his actual skin, such as in the case that you describe.

Explanation:

We do not find any source in the Shulchan Aruch or Achronim which prohibits wearing a Tallis on one’s skin, and on the contrary being that it is meant to be a regular garment worn on the body, it seemingly is meant to be worn over the skin as well, and perhaps this was the common type of Tallis worn in previous times in which their actual clothing were their four cornered garments. The suggestion made by some that it’s forbidden to wear it over one’s skin being that one sweats, and the sweat will then enter the Tallis which is belittling towards it, has no source and on the contrary, we even permit wearing a Tallis in a bathroom and bathhouse and it is not considered belittling at all. As stated above, it is meant to be worn as a garment and garments naturally get dirty and sweaty, and hence stating that there would be such a prohibition would be contrary to its essential purpose of being a garment. Indeed, Rav SZ”A in a response explicitly permits wearing the Tallis over one’s bare skin due to the above reason, and so is likewise proven from a response of the Radbaz and the writings of Rav Shalom Sharabi, the Rashash. On the other hand, we can entertain the idea that some people desire to show their Tallis an extra level of respect being that it is only worn today for the sake of the mitzvah and hence not wear it over their skin in order so it does not absorb sweat. In truth however there is no necessity to resort to this explanation for why some people are careful in this matter, as it is explicitly recorded in the writings of the Arizal as brought in the Achronim that he would wear the Tallis over his undershirt. Now whether this was due to Kabbalistic reasons known to him, or due to the above reason of sweat, we have no idea. However, certainly this is enough of a source for those who desire to be particular in this matter, and so is the tradition amongst Chassidim. Nonetheless, this is not a prohibition to ever wear the Tallis over one’s skin, and hence when necessary one may do so. [It’s important to note that all the applies with regards to wearing a regular Tallis over one’s bare skin. However, with regards to undershirt Talleisim, they contain a further discussion with regards to whether a garment which is sewn on its side or is worn in order to absorb sweat is altogether obligated in Tzitzis, which is beyond the scope of this article.]

Sources: See regarding there being no prohibition to wear over the skin: Radbaz 6:2260; Nehar Shalom p. 24 of Rashash; Halichos Shlomo 3:11; Piskeiy Teshuvos 8 footnote 195-196; Vayeisehv Hayam 1:3; See Nitei Gavriel Aveilus 55:footnote 14 that a garment menat to absorb sweat is exempt from Tzitzis.  See regarding custom of Arizal to we hear the Tallis over his undershirt: Arizal in Shaar Hakavanos Derushei Tzitzis 6 and Peir Eitz Chaim Shaar Hatzitzis 1, brought in Kaf Hachaim 8:43