As often happens in the Gemara, which records actual conversations, discussion of a given topic may segue in a different direction. The first Mishna on today’s daf continues discussing the laws of meal offerings, teaching that the different parts of the minḥa require each other, such that the flour cannot be brought without the oil, nor the oil without the flour; the kometz (the fistful of flour taken by the kohen for sacrifice on the altar) cannot be brought without the frankincense, nor can the frankincense be brought without the kometz.
This leads to the laws that appear in the second Mishna that are not at all related to the laws of meal offerings, rather they are a list of other religious rituals whose different parts make up a greater whole and cannot be divided. It is in this context that we learn that the four different species taken on Sukkot – the lulav, etrog, hadasim and aravot (see Sefer Vayikra 23:40) – require one another and that from a halakhic standpoint, bringing one without the other serves no purpose.
In the Gemara, Rav Ḥanan bar Rava comments that the Mishna’s ruling is limited to a situation where the person does not have all four species. If, however, the person has all four in his possession, then they do not need to be together. The Ba’al Halakhot Gedolot understands this to mean that he would be able to pick them up one by one and fulfill his obligation. Rabbeinu Tam objects to this ruling, arguing that since they are a single mitzva it is not possible that they can be taken separately. He argues that Rav Ḥanan bar Rava’s intention must be to allow them to be taken together, even if they are not tied together.
The Gemara concludes that there is a difference of opinion among the tannai’m regarding this issue. The Ḥakhamim do not require that the four species be tied together, while Rabbi Yehuda requires them to actually be tied together.