Rabbi Mordechai Shain, rabbi of Tenafly’s Lubavitch on the Palisades, has stood in the parking lot every summer morning during drop-off time, greeting parents who have come to bring their children to Camp Gan Israel. He holds a pair of tefillin, and asks any passing fathers if they have had the chance to put on tefillin that day. Many of them, smiling, take him up on his offer each morning.