Makkot 19: Why Ma'aser Sheni Needs the Temple
More on Bikkurim - first fruits: Rav Sheshet says that not placing the produce in the right place next to the altar will prevent it from counting as first fruits, but not reciting the verses from the Torah won't invalidate the first fruits. Which then leads to discussion of whose view he is citing. With comparisons to "bekhor" - first animals - and also to ma'aser sheni (second tithings). Also, from there, the discussion of why ma'aser sheni isn't practiced in the absence of the Temple (eating food in sanctity in Jerusalem could theoretically happen without the Temple, but the aim is to prove why that is not the case, even many years after the Temple's destruction).