Talmud for Shabbat 223:5
מנעל אמנעל לא קשיא הא דקתני חייב חטאת בדאושכפי פטור אבל אסור בדרבנן מותר לכתחלה בדבני מחוזא
[The rulings on] sandals too are not contradictory: when it states that 'one is liable to a sin-offering', it refers to [sandals] of travellers<span class="x" onmousemove="('comment',' Taya'a, specially Arabian caravan merchants. ');"><sup>10</sup></span> tied by cobblers; one is not liable yet it is forbidden', refers to amateur knots<span class="x" onmousemove="('comment',' Lit., 'balls'. ');"><sup>11</sup></span> tied by [the wearers] themselves; 'it is permitted at the outset', refers to sandals in which two go out,<span class="x" onmousemove="('comment',' They are worn by two different people on occasion. Hence they must be tied exactly each time, and therefore the knot is temporary. — In the other two the differences are the same as in the case of shoes. ');"><sup>12</sup></span>
Jerusalem Talmud Shabbat
Ritual impurity biblically is restricted to Jewish persons, food, vessels and tools, and a leprous house. If a vessel or tool was damaged beyond repair, it becomes ritually pure. As usual, impure means “a possible candidate for impurity” and pure “unable to become impure.” Rebbi Jehudah holds that people will repair even serious damage to their shoes if it can be done so as not to be noticed in public. The rabbis hold that even in such cases, people will not repair severely damaged shoes.
R. Jehudah holds that a person will repair sandals when the repair is not immediately visible from the outside. Therefore, if a strap or hole for the shoelaces is torn at the instep, towards the other foot, the shoe remains usable. The majority holds that one torn strap or a partially torn sole can always be repaired. Rebbi Jacob bar Aḥa, Rebbi Tevele, Ḥanin bar Abba in the name of Rav: Practice follows Rebbi Jehuda as far as the Sabbath is concerned104The same statement in Babli, Šabbat 112b..