Q. I have a metrocard (half-price or unlimited). Is it permitted for me to give it to my mechallel Shabbos brother who wants to travel on Friday night? Or should I refuse to give it to him, and let him buy his own and travel regardless?
A. See question 2485 above. Horav Shlomo Miller’s Shlit’a opinion is that if it is unlawful to permit someone else to use your card, certainly you should not allow him to use your card.
Besides, giving him a card to use during Shabbos, could be prohibited as “messayea” or helping someone commit a sin.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a