I am used to the idea of not wearing leather shoes on Yom Kippur. But recently my mother died and the rabbi said that I shouldn’t wear leather shoes for a whole week. Why not?
The Aish Rabbi Replies:
Leather shoes are considered a comfortable attire. Therefore for a mourner, such "comfort" is considered inappropriate. (Talmud – Moed Katan 15; based on Ezekiel 24:17)
On Yom Kippur, the reason is similar, in that we avoid physical pleasures. (Talmud – Pesachim 54b; Yoma 78b; O.C. 614:2, with Mishnah Berurah 5, 15)