Rashi (citing Vayikra Rabah 22:2): One who loves Mitzvos is not satiated from them (he always wants more). Makos 10a - this refers to Moshe, who knew that the cities he separated would not Kolet until the ones in Eretz Yisrael were separated. Still, he seized the opportunity to do the Mitzvah.

Rav Sadya Gaon, Metzudas David: One who loves money (Rashbam - too much) will never have enough; he will never be satisfied with it. Orchos Tzadikim (Sha'ar ha'Teshuvah DH ha'Sheni, citing Koheles Rabah 1:13) - one does not leave the world with half his desire. If he has 100, he desires 200. If he gets 200, he desires 400.

Rashi #1: One cannot eat silver. Maharsha (Bava Basra 25b) - there was a man who loved silver exceedingly. He asked Hashem that anything he touched with his hand should become silver; Hashem agreed. When he came to eat bread, he touched it; it became silver, and he had nothing to eat.

Rashi (citing Vayikra Rabah 22:1): One who loves Torah is not satiated from it (he always wants more).

Ri Kara: There are two Midos. (a) Some love money so much, that if he will gather money like earth, he will not be satiated with it. He will always seek more. He does not like Hamon Rav (to buy many slaves). (b) Refer to 5:9:2:8.

Seforno: I said that people fear the king due to the field (refer to 5:8:2:7). Even though due to the king, people's wealth is guarded, this is not the ultimate purpose. Rather, it is to get grain essential to life, for "Ohev Kesef Lo Yisba Kesef."

Makos 10a #1: Who is qualified to teach Torah to many? One who has all the grain (he knows Tanach, Mishnah, Halachos and Agados ¹ ).

Makos 10a #2: Whoever loves learning with many ² , he will have grain (Torah).

Makos 10a #3: "U'Mi Ohev..." - whoever loves teaching many, he will have Torah. Rebbi said, I learned much from my Rebbeyim, even more from my colleagues, and the most from my Talmidim.

Rav Sadya Gaon: One who gathers [money], he does not have Peros - "Gam Zeh Hevel."

Rashi (citing Vayikra Rabah 22:2): One who loves many Mitzvos, but among them is not a specific and recognized Mitzvah ³ , he has no benefit from it.

Rashi: One who loves great wealth (Ibn Ezra #1 - money, garments and merchandise; he does not love grain), and does not gather Peros, "Gam Zeh Hevel."

Rashi One who loves much Torah, and he has Mikra and Mishnah but not Talmud, he is not satiated from it (he does not know the Halachah).

Ibn Ezra #2, Ri Kara: One who buys many slaves and servants, for he loves to have people serving in front of him, he will not have grain for himself. Metzudas David - his servants will eat all of it.

Rashbam: One who loves great wealth (it is as if the word is repeated, and it says Hamono Shel Mamon), he will not have the abundance that he covets. It is as if it says Lo Sevo'ah (it will not come to him). Also "Lo Sa'avuri" (Rus 2:8) is like Lo Sa'avori.

Rid: One who loves wealth has no grain; he must work the land.

Seforno: One who love among the many things that are not grain, e.g. gems and pearls, and he loves also produce, to aggrandize the honor of his wealth and household, this is Hevel; he loves Hevel.

Ibn Ezra: This is Hevel, just like one who loves Kesef, and gathers only silver and gold.

Rashbam: He is like one who toils to acquire too much money. It suffices to be financed honorably without great wealth.

Ri Kara: Both one who loves money and is never be satiated with it, and one who loves to buy many slaves, and lacks food, both are Hevel.

Rid: Even though working the land is greater than any benefit, also it is Hevel. Refer to 5:10:1:6.

R. Avigdor: One who learned himself, but did not teach others, it is Hevel. From here they said, a Rav receives reward for learning only after he teaches another. Some say, the Rav receives a reward of 1000, and the Talmid receives 200 - "ha'Elef Lecha Shlomo u'Masayim l'Noterim Es Piryo" (Shir ha'Shirim 8:12).

Refer to 5:9:2:11.

Metzudas David: Even though he gives to others enough [food] for them, it is still Hevel, for it is improper to squander so much.