I have a car key from which I can take off the electric “clicker” that starts the ignition of the car and opens the doors; the problom is all the doors the key opens turn on some light in the car- even the trunk; if I drive to shul erev shabbat can I keep this key in my pocket until after shabbat, or is this forbidden (mukztah kli shmaelachto l’issur). And in general, can one intentionally carry a kli shemelachto l’issur in one’s pocket?
Answer:
It is permitted to carry the keys in one’s pocket, provided that the pocket is a “separate entity” sewed onto the item of clothing, such as a the pockets of pants, or inside pockets of a jacket.
The keys should not not be carried in a standard shirt pocket, where the shirt itself holds the item, making the shirt a “basis” for the keys.
However, once you get home, or to a place where the keys can be shaken out without fear of losing them or getting them stolen, you should shake them out, and the keys should not be left in the pocket intentionally after there is a reasonable opportunity to shake them out.
Sources:
Mishnah Berurah 310:29.
