And on the tenth day of this seventh month, there shall be a holy convocation for you, and you shall afflict your souls… (Numbers 29:7)
The Mishnah details five ways in which we must afflict ourselves on Yom Kippurwhich includes refraining from neilat hasandal, wearing shoes (Yoma 73b). The Gemara describes how some sages would wear bamboo shoes instead, implying that the prohibition is to only refrain from wearing leather shoes (ibid. 78a-b).
The majority of later authorities ruled that non-leather shoes are not considered shoes according to Jewish law and it should therefore be permissible to wear them. However, the Torah implies that refraining from non-leather shoes is intended to ‘afflict our souls’. In the spirit of this law, should comfortable non-leather shoes be allowed?
The 3rd century sage Abaye argued that it is not only leather shoes which are prohibited but anything that provides a similar or greater level of comfort. His contemporary Rava argued that the only explicit prohibition is to wear leather shoes (ibid.).
Maimonides (d. 1204) argued that it is permissible to wear non-leather shoes provided that one still feels as if he is walking barefoot (Yom Kippur 3:7). This would presumably prohibit modern day trainers and the like. Yet both Rabbi Yitzchak Alfasi (known as the ‘Rif’ d. 1103) and Nachmanides (known as the ‘Ramban, d. 1270) did not prescribe this caveat.
The Shulchan Aruch (Code of Jewish Law, published in 1565) rules in accordance with the Rif and the Ramban and permits all types of non-leather shoes (Orach Chaim 614:2). The Mishnah Berurah (Rabbi Yisrael Meir Kagan, d. 1933) notes that in his time many were strict in accordance with Maimonides and refrained from wearing shoes made from felt as they were too comfortable. Yet he concludes that this was only a stringency and that comfortable non-leather shoes are permitted, especially if one has to walk outdoors (ibid. 614:5).
Jewish thinking does not consider unnecessary physical affliction as an ideal way to serve God. While it is admirable to go beyond the letter of the law, one must focus on the most important aspects of Yom Kippur: teshuvah and one’s own personal growth.