The “Tefillin for Every Hostage” project was launched by the mother of hostage Bar Kupershtein, held in Gaza for 600+ days. Volunteers who previously didn’t wear tefillin (phylacteries) choose a hostage in whose name they will wear them daily for. “Bar Tefillin” stations have been set up all over Israel.
https://www.jns.org/herzog-hosts-participants-of-tefillin-for-hostages-project/