Several approaches in the gemara to explain the argument between the Tana Kama and Rabban Gamliel regarding one who finds tefillin on Shabbos. Rashi’s addition that is difficult to understand. Introducing the sugya of Zaken Mamrei as an apparent contradiction to this sugya. Resolving the contradiction. A further gemara. In light of the above, Rashi can be understood. This drasha is a small section of a larger drasha that the Beis Yitzchak zt”l learnt with his son, R’ Aharon zt”l when he turned Bar Mitzva. It was printed in his great sefer, “Beis Yitzchak”, Orach Chaim 19. He begins the drasha by requestion that lomdey Torah and yirei Hashem learn this drasha with their sons. At the end of this drasha there is a powerful message that relates to chinnuch and to being careful to avoid issurim.