Gemara

Yonason: I have a tradition from Moshe that it is better to hire himself out and do Avodah Zarah, than to be supported by others.

He thought that this means idolatry. Really, it means work that is foreign to him.

Rav (to Rav Kahana): Flay a carcass in the market for wages. Do not consider yourself too important, and that this is a disgrace for you.

Bava Metzia 84b: R. Elazar b'Rebbi Shimon's wife was angry that he had 'squandered' her father's money by bringing afflictions on himself; she left him. Some sailors were saved from great danger in the merit of R. Elazar; they gave to him a great gift. He told his wife 'my wealth exceeds that of your father's house' - "Haysah k'Aniyos Socher" (the Torah supports those who learn it).

Kesuvos 105a: Giving a gift to a Chacham is like bringing Bikurim.

Avos 1:13: One who uses the crown (of Torah for personal benefit) will cease from the world.

Avos 4:5: Anyone who benefits (financially) from Torah removes his life from the world.

Chulin 44b: R. Elazar would not accept gifts from the Nasi or invitations to eat there due to "V'Sonei Matanos Yichyeh";

R. Zeira declined gifts from the Nasi's house, but accepted invitations to eat there. He reasoned that they are honored by his presence.

Chulin 134a: A bag of money was sent to support Rabanan; R. Ami acquired it.

Question: "V'Nosan" - a person should not take for himself!

Answer #1: He acquired it on behalf of the poor.

Answer #2: The head (of the academy) may take for himself;

(Beraisa): "Veha'Kohen ha'Gadol me'Echav" - the Kohen Gadol must be greater than the other Kohanim in beauty, Chochmah, and wealth;

Others say, if necessary, the other Kohanim give money to him to make him the wealthiest Kohen.

Rishonim

Rambam (Hilchos Matanos Aniyim 10:18): One should avoid taking from people if at all possible, even if he must suffer. Great Chachamim chopped wood, carried beams, drew water, or were smiths rather than request from the Tzibur. They did not accept offers of money.

Rambam (ibid.): In every generation there have been very poor and very rich people. Surely, the rich were willing to give to the poor! Rather, the poor preferred to subsist on their meager incomes. Chachamim like Hillel and R. Chanina ben Dosa were very poor. They saw that it would be Chilul Hash-m to take money from people, lest Torah be cheapened in people's eyes, i.e. Torah would look like a profession from which one supports himself.

Rebuttal (Kesef Mishneh): One cannot learn from Hillel! At first, he was one of thousands of Talmidim. Perhaps support was given only to the most known Talmidim, or those who could not support themselves. Surely, when he taught Yisrael he had ceased to chop wood! R. Chanina ben Dosa had no need to take from people. Shamayim would grant all his desires, just he did not want to benefit from this world.

Rambam (ibid.): "Haysah k'Aniyos Socher" - the Torah supports a Chacham who is physically unable to support himself. Otherwise, he may not take from others.

Rebuttal (Kesef Mishneh): If so, this is no praise of Torah. Sick and handicapped people always find people to support them, even if they are not Chachamim! Also, R. Elazar b'Rebbi Shimon brought afflictions on himself; he caused his afflictions depart when he wanted to learn, but he did not do so to preclude the need to benefit from Torah!

Defense of Rambam (Einayim l'Mishpat Bava Basra 110a:3): R. Elazar b'Rebbi Shimon was concerned lest he needed a Kaparah for informing on sinners. Alternatively, he accepted on himself the afflictions due to come on Kelal Yisrael, so it was proper that they support him.

Question (Kesef Mishneh): The Rambam connotes that a healthy Chacham should not take a gift. Giving a gift to a Chacham is likened to bringing Bikurim! It was customary to give gifts to Nevi'im (Shmuel 1:9:7-8).

Answer (Einayim l'Mishpat ibid.): We learned that giving to a Chacham is like Bikurim from Elisha (Melachim 2:4:42), i.e. in a famine year. Perhaps it applies only when the Chacham cannot support himself! Since people give small gifts to an important person, even if he is ignorant, this is not considered benefit from Torah. Elisha (took a big gift, but he) himself did not benefit from the gift. He give it to his Talmidim, who could not support themselves while learning.

Kesef Mishneh: When R. Ami took the money sent to the Beis Medrash (Chulin 134a), the question was only why he took it by himself, rather than letting others give it to him.

Rambam (ibid.): The Gemara says that one who wants to benefit from others like Elisha may do so. This permits occasionally accept lodging or a meal, but not regular stipends!

Poskim

Shulchan Aruch (YD 255:1): One should avoid taking Tzedakah if at all possible, even if he must suffer. Chachamim commanded to make Shabbos like Chol rather than take Tzedakah.

Birkei Yosef (DH v'Al): Chachamim taught that 'one should not take from people' to include even gifts. However, for the preservation of Torah it was permitted. Tana'im and Amora'im were stringent not to take; this was beyond the letter of the law.

Yam Shel Shlomo (Chulin 3:9, brought in Taz 246:7): There is a Heter to lend to Nochrim on interest 'Kedai Chayav' (for as much as he needs to live). Tosfos (Bava Metzi'a 70b DH Tashich) says that nowadays due to government taxes, there is no limit. We can say the same to justify taking money to learn even if one has money. Even those exempt from taxes have great expenses to teach Torah to their children and to marry off daughters to Chachamim.

Taz (7): One who is not overly wealthy may rely on this to take a gift of any amount. However, if he already has enough to last his lifetime, he may not take gifts.

Rema (246:21): The custom is to support the Rav of the city, lest he need to work in public and disgrace Torah in the eyes of the masses. This is only if the Chacham needs assistance. Some are more lenient to allow a Chacham and his Talmidim to receive support in order to engage in Torah comfortably.

Bach (DH u'Mah she'Chosav Kol, and Sof ha'Siman): We learn from the Kohen Gadol that a Rosh Yeshiva may take gifts to become rich to give more clout to his words.

Question: Kesuvos 105a was forced to say that judges in Yerushalayim received extra money only if their stipends did not suffice!

Answer (Bach DH v'Ha): Those judges did not need to be rich to give clout to their words.

Rebuttal (Taz 7): If people may give gifts to the Av Beis Din, one who knows that he will have a judgment later will give a gift long beforehand to bias the Av Beis Din! If he takes gifts, he will not receive any other reward for his Torah. All the more so, money hungry Chachamim who demand money disgrace Torah and those who learn it!

Rema (ibid.) Nevertheless, it is Midas Chasidus to support oneself and learn. This is a gift from Shamayim; not everyone can do so and become a Chacham.

Source (Gra 65): R. Elazar and R. Zeira declined gifts from the Nasi due to "V'Sonei Matanos Yichyeh".

Rema (ibid.): The Heter is to receive from the Tzibur, but one may not take gifts from people.

Shach (21): The Kesef Mishneh, Maharshal and Bach permit even gifts from people. "V'Sonei Matanos Yichyeh" does not imply that one who takes gifts will die.

Rema (ibid.): Giving a small gift to a Chacham is likened to bringing Bikurim; it is customary to give such gifts to a great person, even if he is ignorant.

Birkei Yosef (DH Kol): If the giver himself wanted to give, one who refuses to accept withholds Chesed. Shmuel ha'Navi did not take, for he feared that people offered because they were embarrassed not to. Even though some Chachamim refused to take due to "v'Sonei Matanos Yichyeh", a traveler does not have his Kelim and is like an Oni, so he may take.