Question: If one’s shoelaces come out of one’s shoes on Shabbat, may one re-lace them on Shabbat or is this forbidden?
Answer: Maran Ha’Shulchan Aruch (Chapter 317, Section 2) writes: “If the straps fall out of one’s sandals on Shabbat, one may return them to their place.” This means that if the straps were already fastened to the shoe and then fell out, one may re-fasten them on Shabbat and this poses no concern of either tying, sewing, or “repairing a vessel” on Shabbat.
Nevertheless, the Mishnah Berura points out that if the shoes are new, one may not re-lace them on Shabbat, for this can be considered “repairing a vessel,” i.e. finishing off the shoes by making them ready for use as a result of re-inserting the laces.
On the other hand, some modern-day Poskim rule leniently regarding today’s shoes, for many of the shoes on the market today have a metal reinforcement around the hole where the lace is placed making inserting the laces into the shoe quite easy and effortless, thus, leaving no room for concern whatsoever. The author of the Responsa Be’Tzel Ha’Chochma and his brother the author of the Responsa Be’er Moshe write lengthily about this matter and conclude that their father zt”l ruled leniently on this issue.
Another reason for leniency on this matter is because shoes nowadays can be worn even without laces. Only in the generations of the Sages and the early Poskim were the shoes made in such a fashion that without laces, the shoe would fall off of one’s foot (some sort of sandal). However, regarding our shoes which are enclosed from all sides and the laces serve only to tighten them to one’s feet, re-lacing them is not considered “repairing” or finishing off the shoe at all.
Halachically speaking, Maran Rabbeinu Ovadia Yosef zt”l writes that there is room for leniency only regarding old shoes; however, regarding new shoes, one shoes not re-insert laces into the holes on Shabbat, for this is similar to “repairing a vessel”. Nevertheless, since many are lenient with regards to new shoes as well, if one does so, one indeed has on whom to rely.
Summary: If a shoelace comes out of one’s shoe on Shabbat, one may re-insert it into the shoe. Even if the shoelace is new, there is room for leniency. However, if the shoes themselves are new and the laces have never yet been inserted into the shoes, there are those who rule stringently and forbid lacing these shoes on Shabbat and one should do so before the onset of Shabbat. One who acts leniently to and does so on Shabbat in a situation of need indeed has on whom to rely.