Musar for Pirkei Avot 4:5
רַבִּי יִשְׁמָעֵאל בְּנוֹ אוֹמֵר, הַלּוֹמֵד תּוֹרָה עַל מְנָת לְלַמֵּד, מַסְפִּיקִין בְּיָדוֹ לִלְמֹד וּלְלַמֵּד. וְהַלּוֹמֵד עַל מְנָת לַעֲשׂוֹת, מַסְפִּיקִין בְּיָדוֹ לִלְמֹד וּלְלַמֵּד לִשְׁמֹר וְלַעֲשׂוֹת. רַבִּי צָדוֹק אוֹמֵר, אַל תַּעֲשֵׂם עֲטָרָה לְהִתְגַּדֵּל בָּהֶם, וְלֹא קַרְדֹּם לַחְפֹּר בָּהֶם. וְכָךְ הָיָה הִלֵּל אוֹמֵר, וּדְאִשְׁתַּמֵּשׁ בְּתָגָא, חָלָף. הָא לָמַדְתָּ, כָּל הַנֶּהֱנֶה מִדִּבְרֵי תוֹרָה, נוֹטֵל חַיָּיו מִן הָעוֹלָם:
R. Yishmael, his son, says: If one learns in order to teach, it is given him to learn and to teach. [This is the correct version. Its meaning: If one learns in order to be constantly involved in Torah, not thinking to engage in lovingkindness with others, like Rava (Rosh Hashanah 18a) who occupied himself with Torah but not with lovingkindness, even though he should also do the latter, still, it is given him to learn and to teach, as per his intent], and if one learns in order to do, [wanting to study Torah but also to engage in lovingkindness, like Abbaye, who engaged in Torah and in lovingkindness,] it is given him [to fulfill his intent and] to learn and to teach, to keep and to do. [There are some who explain "If one learns in order to teach," in order to be called "Rabbi," and who read "it is not given him to learn and to teach," but in most books I have found it as in the first version, which is the correct one.] Do not make them (words of Torah) a crown to aggrandize yourself with. [Do not say: I will learn in order to be called "Rabbi" and to sit at the head, but learn from love, and honor is bound to come], (and do not make them) a spade with which to dig. [Do not learn Torah in order to make a livelihood of it. For one who does so profanes the holiness of Torah and is liable to death at the hands of Heaven, as is one who derives (personal) gain from sacred property. And the teachers of schoolchildren take pay only for watching them alone, that they not damage things, and for teaching them cantillations, which a teacher is not obligated to exert himself to do. But it is forbidden to take pay for teaching Torah, as it is written (Deuteronomy 4:14): "And the L rd commanded me at that time to teach you statutes and judgments" (Ibid. 5): "as the L rd my G-d commanded me" — Just as I, gratis, you, too, gratis. And a judge, too, is forbidden to take a fee for ruling, but only an "absentee fee," that it be manifest that the fee represents what he loses by absenting himself from his work to hear the pleas of the litigants (provided that he takes an equal amount from both. If he takes more from one than from the other, his rulings are nullified.) As to the Torah permitting a Torah scholar to benefit from words of Torah, this applies to selling his works in the marketplace before others do and also to his exemption from all (personal) taxes, impositions, and property taxes. The congregation must pay even the head tax for him. And even if he is wealthy and has much money he may claim exemption by law. And if a Torah scholar is sick and steeped in affliction and the congregation proffer large gifts to him in honor of his Torah, it is a mitzvah for him to take them. And this is not in the category of profiting from words of Torah since it is impossible for him to sustain himself otherwise. And, likewise, a Torah scholar who was appointed a parnas (community leader) or rosh haseder by the congregation, and who occupies himself with the needs of the congregation, may take a wage from them, even what is far in excess of what he needs for a livelihood, so that he be great, and feared and awe-inspiring to them, as we said with the high-priest of whom it is written (Leviticus 21:10): "who is greater than his brothers," which the sages expound: "Make him great from his brothers." His brother Cohanim are to make him wealthy from what is theirs. As to the early sages, who abstained from this, this was out of their chasiduth but it is not the din.] And this is what Hillel was wont to say: "One who 'uses' the crown (of Torah) passes away" — whereby we are taught that one who exploits words of Torah "takes his life" from the world.