In the previous shiur, we discussed in depth the drash (we also raised the question of whether this is a true drash or an asmachta) brought by the gemara to answer the opening question of the sugya: What is the (Torah) source for the requirement to make a blessing before eating food? We also learned the pesukim that are the context of this drash and discussed the mitzva of reva’i, the fourth year fruit of a planted tree. At the end of the shiur we learned the Rashi on the words קדש הלולים, which reminded us that what we learn from the drash so far applies only to reva’i and not to any other kinds of fruit. Please review this material; if there are questions I will be happy to discuss them at the beginning of this shiur.
In this shiur, we will now encounter the difficulty (kushya) raised by the amoraim in the gemara with this drash: that it is unavailable because the basis for the drash is used already for learning something else. We will spend time understanding the background to the kushya, including learning the Rashi. All of this is on Berachot 35a.