Sukkah Chapter 3, Mishnah 9. Our Mishnah deals with the waving of the lulav: where, and at which point in the recitation of Hallel, the wavings were performed.
Where they would wave:
"Hodu la'Hashem" - at the beginning of the chapter, Psalm 118.
"Hodu la'Hashem ki tov ki l'olam chasdo" - at the end of that same chapter.
"Ana Hashem hoshia na" - which is not our practice.
This is the opinion of Beis Hillel.
The testimony of Rabbi Akiva:
Rabbi Akiva testifies: I was watching Rabban Gamliel and Rabbi Yehoshua at the time of prayer, and while all the people were waving their lulavim, they - Rabban Gamliel and Rabbi Yehoshua - waved only at "Ana".
What is the dispute among the commentators in explaining this testimony?
Some explain it literally: that they waved only at "Ana", and not even at "Hodu la'Hashem ki tov".
Others explain that it comes only to teach that they held like Beis Hillel and not like Beis Shammai, meaning that they did not wave at that particular "Ana", but they certainly did wave at "Hodu la'Hashem".
One who comes in from the road:
Someone who was traveling and did not have a lulav in hand to take at the time of his prayer, when he reaches his home he takes it then, even though he has already recited Hallel and this is no longer within Hallel. He did not have the opportunity at the proper time, and nevertheless he should take it.
And the ruling here is: even if he is sitting in the middle of his meal at his table and eating, he need not interrupt his meal in order to take the lulav and esrog. He had no opportunity to take it in the morning - he takes it in the afternoon, since the entire day is fit for the mitzvah of lulav.
In summary: In this Mishnah we learned where the wavings of the lulav are performed during Hallel according to Beis Hillel, the testimony of Rabbi Akiva regarding Rabban Gamliel and Rabbi Yehoshua and the two explanations of it, and the law of one who comes in from the road - that he takes the lulav at home even after Hallel, and does not interrupt his meal for this, since the entire day is fit for the mitzvah of lulav.