Musar for Pirkei Avot 2:2
רַבָּן גַּמְלִיאֵל בְּנוֹ שֶׁל רַבִּי יְהוּדָה הַנָּשִׂיא אוֹמֵר, יָפֶה תַלְמוּד תּוֹרָה עִם דֶּרֶךְ אֶרֶץ, שֶׁיְּגִיעַת שְׁנֵיהֶם מְשַׁכַּחַת עָוֹן. וְכָל תּוֹרָה שֶׁאֵין עִמָּהּ מְלָאכָה, סוֹפָהּ בְּטֵלָה וְגוֹרֶרֶת עָוֹן. וְכָל הָעֲמֵלִים עִם הַצִּבּוּר, יִהְיוּ עֲמֵלִים עִמָּהֶם לְשֵׁם שָׁמַיִם, שֶׁזְּכוּת אֲבוֹתָם מְסַיַּעְתָּן וְצִדְקָתָם עוֹמֶדֶת לָעַד. וְאַתֶּם, מַעֲלֶה אֲנִי עֲלֵיכֶם שָׂכָר הַרְבֵּה כְּאִלּוּ עֲשִׂיתֶם:
R. Gamliel, the son of R. Yehudah Hanassi says: Torah study is "becoming" with derech eretz [labor or business], for the toil of both causes sin to be forgotten. [For the Torah attenuates a man's strength and labor breaks the body, and, as a result, the evil inclination departs from him. And if you would ask: If so, let him toil in Torah always and its toil would banish sin. Why, then, is labor needed? It, therefore, must be stated:] And all Torah without labor is lost in the end and foments sin. [For one cannot live without a livelihood and his end will be to rob men, and his learning will be forgotten.] And all who toil with the congregation, let them toil with them for the sake of Heaven. For the merit of their [the congregation's] fathers and their righteousness (which) stands forever, [and not the exertions of the toilers] will help them, [the toilers, to bring their righteousness to light.] And you, [the toilers], I will bestow great reward upon you, as if you had done it. [Even though this good was effected not through your deeds, but through the merit of the fathers of the congregation, I will bestow reward upon you as if you had wrought this great salvation in Israel, since you toil for the sake of Heaven. Alternately: all who toil with the congregation to compel them to (the performance of) a mitzvah — to charity or the redemption of captives — let them do so for the sake of Heaven. For the merit of the fathers of the congregation will help them give what they (the toilers) impose upon them — even great wealth. And the charity that they (the congregation) do will stand for them forever. And you who compel the congregation towards this mitzvah — I shall bestow reward upon you as if you had performed the mitzvah with your very wealth. And Rambam explains: "And I will bestow upon you reward as if you had done them" — If in your toil with the congregation, you have omitted the performance of a certain mitzvah, I will bestow reward upon you as if you had performed that mitzvah.]