A Novel Insight into the Prohibition of Wearing Leather Shoes on Yom Kippur

The Shulchan Aruch (O.C. 614:2) rules: “It is forbidden to wear a sandal or shoe of leather... but those of reed, straw, cloth, or other materials are permitted.” It is clear that only leather shoes are forbidden. The meforshim ask: Why is the prohibition limited to leather shoes, especially when sometimes other shoes are more comfortable than leather?

Perhaps we can explain this with the following idea:

The Torah says (Shemos 3:5): “Remove your shoes from your feet, for the place upon which you stand is holy ground.” The Medrash Rabbah (2:6) writes: ""Remove your shoes' wherever the Shechinah appears, wearing shoes is forbidden. We find the same thing with Yehoshua (5:15) and with the Kohanim in the Beis HaMikdash.” The question is, what is the connection between the Shechinah appearing and wearing shoes?

The Be'er Yosef, citing the Shelah, explains: In creation there are four levels, 1) Domem, lifeless products, 2) Tzomeach, plants, 3) Chai, living products such as animals, 4) Medaber, living beings that know how to speak, i.e. human beings.

Each higher level rules over the lower level. Plants draw sustenance from the earth. Animals eat plants. Humans eat animals. The fact that humans slaughter and eat animals shows that it has dominion and rules over them. If humans rule over animals, certainly they rule over the other levels of creation as well.

However, the clearest sign that human beings have dominion over all other levels of creation is the fact that they are able to remove the skin of an animal and wear it under their feet. By wearing animal skins under one's feet (i.e. leather shoes), one shows he has dominion over the other levels of creation. (The Shlah goes on to explain that this is why the berachah of שעשה לי כל צרכי, refers to shoes.(

Based on this, we can understand why it is forbidden to wear leather shoes when the Shechinah appears. Since wearing leather shoes demonstrates that one has dominion over the other levels of creation, when there is the appearance of the Shechinah and it is like one is in the palace of the King, it is forbidden to wear leather shoes as it is forbidden to display dominion in the palace of the King. This is why Moshe had to remove his shoes, why Yehoshua removed his shoes and why Kohanim serve barefoot in the Beis HaMikdash.

With this yesod, Rav Shlomah Zalman Auerbach zt”l (Halichos Shlomah, at the end of the sefer in a Maʼamer titled שעשה לי כל צרכי( explains why it is forbidden to wear leather shoes on Yom Kippur and on Tisha B'Av. The prohibition is not about comfort, rather, it is about not displaying dominion and Yom Kippur and Tisha B'Av are days that one shouldn't be demonstrating dominion. Since this is the reason, we can understand why it is limited to leather shoes, and not any type of shoe.

This is also the reason why an avel is forbidden to wear leather shoes. Mourning requires humility, not dominance, therefore, an avel shouldn't wear leather shoes and since it is about not showing dominance the prohibition is limited to leather.