(Mishnah): A stolen or dry Lulav is invalid.

If it was worshipped as an idol or comes from a city that must be destroyed (due to the idol worship that exists there), it is invalid.

If the top is cut or the leaves are split, it is invalid.

If the leaves are separated, it is valid. R. Yehuda says that one should tie it on top.

Tzini branches of Barzel Mountain are valid.

If a Lulav is three Tefachim long with room to shake it, it is valid.

(Gemara - Beraisa - R. Chiya): The Pasuk states (Vayikra 23, 40), "You shall take for yourselves" - it must belong to you and not be stolen.

R. Levi: One who uses a stolen Lulav is comparable to a person who honored the governor with a gift of food and it was discovered that it already belonged to the governor.

They said to him: His advocate (the Lulav is supposed to 'remind' Hash-m of our merits) becomes his prosecutor (as Hash-m is 'reminded' of this person's theft).

R. Elazar said that a Shofar used for idol-worship or from a city that must be destroyed is valid.

R. Chiya taught that it is valid; R. Hoshiya taught that it is invalid. All agree that a Lulav with these flaws is invalid.

Question: Why is a Shofar different from a Lulav?

Answer (R. Yosa): The Pasuk states about Lulav, "You shall take for yourselves" - it must be yours and it may not come from something that has a prohibition to derive benefit. However, the Pasuk states about Shofar (Bamidbar 29, 1), "It shall be a day of sounding the Shofar for you" - this implies that in all cases one fulfills the Mitzvah of Shofar (even when using a Shofar that has a prohibition upon it to derive benefit).

Answer #2 (R. Elazar): There (Lulav), one fulfills his obligation with the item itself; here, it is with the sound of the Shofar that he fulfills his obligation; does the prohibition against deriving benefit apply to sound?

They disagree when he stole it after it was already filed down (and shaped for use), but if he stole it and filed it down, he only owes the owner its monetary value.

Query: If he stole a Lulav from one person, a Hadas (myrtle) from a second person and an Aravah (willow branch) from a third person and tied them all together, did he acquire it through the change that he made or since we say that Lulav does not need to be tied, he did not acquire it?

Let us prove it from here - A stolen Sukah - one Beraisa teaches that it is valid and one says invalid.

R. Simon quoting R. Yehoshua B"L: The Beraisa that taught that it is valid refers to when he stole land (and is act of building a Sukah acquired the land. The Beraisa that taught that it is invalid refers to when he stole Schach.

Question: Why did he not acquire the Schach when he tied it? This shows that tying is not called a change that makes an acquisition.

Rabbanan of Kisarin quoting R. Yochanan: In both these cases it is invalid. What is the case of a stolen Sukah? When he enters a Sukah without the owner's permission.

It is like the case of Gamliel Zuga who build a Sukah in the marketplace. R. Shimon ben Lakish passed by and said to him, "Who permitted you to do this?"