Gemara

Question: What do we learn from "Boz Yavuzu Lo (they will scorn him)"?

Answer (Ula): This does not refer to Shimon, the brother of Azaryah (who was called so, for his brother supported him), nor to R. Yochanan (who was supported by the Nasi). Rather, it refers to Hillel and Shevna.

(Rav Dimi): Hillel engaged in Torah. His brother Shevna engaged in business.

Shevna: Let us be partners, and split the rewards (in this world and the next).

A voice from Heaven: "If a man would give all his wealth for love (Torah learning), they will scorn him."

Berachos 34b (R. Chiya bar Aba): All prophetic visions of future reward were only for one who marries off his daughter to a Chacham, or does business on behalf of a Talmid Chacham, or lets a Talmid Chacham benefit from his possessions. No prophet ever had a vision of the reward in the World to Come for a Talmid Chacham -- "Ayin Lo Ra'asah Elokim Zulasecha Ya'aseh li'Mechakeh Lo."

Pesachim 53b (R. Yochanan): People who are Matil Mal'ei l'Kis Chachamim (help them profit in business) merit to sit in the Heavenly Yeshiva - "Ki b'Tzel ha'Chachmah b'Tzel ha'Kasef."

Rishonim

Perush ha'Mishnayos (Avos 4:6): A Chacham may not take gifts. Others may be Matil Mal'ei l'Kiso, i.e. they sell his merchandise before anything else.

Rashi (Pesachim 53b DH Matil): Matil Mal'ei l'Kis Chachamim is to give (lend) to them merchandise to profit from it.

Rashi (Zevachim 2a DH Shimon): Azaryah stipulated with Shimon that he will supply Shimon's needs, and receive a share in the reward for his Torah.

Magen Avos (1:14): Shevna is scorned, for he did not offer to support Hillel before he learned.

Maharsha (21a DH Mai): Shimon and R. Yochanan were scorned in this world (they were called by the name of their supporters) and the next (they lost half the reward for their learning. Ula teaches that one should not do like Shimon or R. Yochanan. Rather, he should refuse, like Hillel.)

Poskim

Shulchan Aruch (YD 246:1): One who cannot learn, because he does not know how to learn at all, or due to distractions, should support others who learn.

Rema: It is considered as if he himself learned. Levi can stipulate with David that David will learn and Levi will supply his income and share the reward.

Shach (2): They share the reward, and also the money that Levi earns.

Gra (7): Bereishis Rabah (99:11) says that Zevulun is mentioned before Yisachar in Yakov's Berachah because he did business and fed Yisachar, who learned. Moshe said "rejoice Zevulun in your going out (because you have a share of) Yisachar in your tents." Shimon is called 'Azaryah's brother', even though he was greater than Azaryah, because Azaryah supported him.

Gra (7, citing Vayikra Rabah 25a): Had it said 'Torah is a tree of life for those who toil in it', and 'cursed is he who will not learn the Torah', (many of) Yisrael would falter. Rather, Torah is "a tree of life la'Machazikim Bah (for those who support it)', and "cursed is he who Lo Yakim (will not uphold) the Torah." If one is Chayav Misah for a sin, he should learn more than he used to, and he will live. If he does not learn, he should become a community leader and overseer of Tzedakah, for it says "... la'Machazikim Bah" and "... Asher Lo Yakim." Even if one learned, taught and fulfilled, but he could have protested (against sin) or supported Torah but did not, the above curse applies. ." If one did not learn, teach or fulfill, and was not able to support Torah but (struggled and) supported, and was not able to protest but (anyway) he protested, the Berachah "... Asher Yakim" applies to him.

Rema (ibid.): If David already learned, he cannot sell a share (of the reward) for money that Levi will give.

R. Yerucham (Toldos Adam v'Chavah 2:5, cited in Bedek ha'Bayis): David can stipulate before learning that Levi will support him and get half the reward, like Yisachar and Zevulun. David cannot stipulate after learning - "if a man would give all his wealth...", like it says about Hillel and Shevna. The Meforshim say that David loses (if he stipulates); he forfeits his share.

Maharam Alashkar (101, cited by R. Akiva Eiger): Rav Hai Gaon said that it is folly to think that one can sell the reward for fasts or Mitzvos that he did. "Tzidkas ha'Tzadik Alav Tihyeh v'Rish'as ha'Rasha Alav Tihyeh" - just like one is not liable for another's sins, one does not receive another's merits. Is reward for Mitzvos something a person can carry around and give to whom he wants?! Reward is honor for one's deeds. One receives the Shechinah; he is praised and stands in the place appropriate for him. If one sold the reward for his fast, he lost it. He did not fast for Hash-m, rather, for money. Perhaps he will be punished for making Hash-m's name a mockery and an axe to use for food. However, surely one who pays teachers to teach, and helps support those who learn so they will be free to learn, has a great reward. One who tries to buy another's reward is disgraced, like Shevna.

Esh Da'as (Parshas Vayelach, cited by R. Akiva Eiger): One who paid 100 gold coins for another's share in Livyasan should not rejoice. The seller should mourn having made the world to come a joke, and sold eternal life for money. Eating from Livyasan is not physical. It is an eternal delight due to one's Mitzvos. Once he sold his share, he lost it. The buyer gets reward for showing how dear is the world to come to him, that he spent a vast sum for it.

Yefe To'ar (on Vayikra Rabah 25:1 DH v'Eis): Three verses allude to three ways of supporting Chachamim. "B'Tzel ha'Chachmah..." alludes to Matil Mal'ei l'Kis Chachamim, i.e. one who lends to them money to be able to buy merchandise which can be sold for a profit. He merits to sit in the Heavenly Yeshiva. "...V'Asu Tzedakah...; Ashrei Enosh Ya'aseh Zos" alludes to one who gives Tzedakah to Chachamim. "... La'Machazikim Bah" refers to those who get others to give, i.e. community leaders and overseers of Tzedakah.

Esh Da'as (ibid.): "B'Tzel ha'Chachmah..." refers to one who gives half his income to the Chacham. He gets half the reward, like Yisachar and Zevulun - "Shneihem Mele'im Soles" (Bamidbar Rabah 13:17). "Ashrei Enosh Ya'aseh Zos" alludes to supplying a Chacham's needs, like Azaryah did for Shimon. "La'Machazikim Bah" refers to one who gives after the Chacham learned. He does not get the reward of Torah, just the Mitzvah of supporting Torah.

Aruch ha'Shulchan (8): Surely, reward for the world to come cannot be sold. When they join from the beginning, the two did the Mitzvah together, like Yisachar and Zevulun. There were visions of the future reward for one who does business for a Chacham, but not for the future reward of a Chacham.

Chelkas Yoav (YD 137:5): One may make a Yisachar-Zevulun partnership with Ma'aser Kesafim, for this gives merely a good reward in the world to come. Even without stipulating, one who benefits a Chacham clings to the Shechinah, and it is as if he brought Temidim... Ma'aser Kesafim is more lenient than Ma'aser Oni, from which one has Tovas Hana'ah. Rashi in Zevachim says that Azaryah stipulated with Shimon, but Rashi in Sotah connotes that it suffices to intend to have a share in his learning. Sefer Chasidim (585, cited in Shach 242:66) says that if Ploni teaches Yosef only because Kalev pays him, Yosef returns Kalev's Aveidah before Ploni's. This is due to Tovas Hana'ah, without a Yisachar-Zevulun partnership!

Igros Moshe (YD 4:37 from DH u'Sfeikah): The Shach (2) connotes that they share the earnings and reward equally. If Zevulun can supply only half of Yisachar's needs, he gets half the reward for the half of the year that Yisachar can learn without working. If he could supply it all, but does not, he gets only reward for supporting Torah. The same applies if Yisachar has 200 Zuz, but he would learn less without Zevulun's help. The partnership gives to Zevulun an equal share in the additional learning Yisachar achieved due to Zevulun's help. This refers to reward of Torah in this world and the next, and protection from sin.