Why the 3,000-year-old tradition of wearing hidden scrolls is making a comeback

One of the most sacred objects in Judaism is made of skin from a bull's neck. It’s called tefillin, and each black box contains scrolls that must be written by hand. Now, demand for these prayer objects has soared since the war in Israel and Gaza that erupted on October 7 — mostly from less religious Jews, including Israeli soldiers headed into battle. So what does it say inside these little boxes? And why are so many people trying to get their hands on them?