Talmud for Pirkei Avot 1:15
שַׁמַּאי אוֹמֵר, עֲשֵׂה תוֹרָתְךָ קֶבַע. אֱמֹר מְעַט וַעֲשֵׂה הַרְבֵּה, וֶהֱוֵי מְקַבֵּל אֶת כָּל הָאָדָם בְּסֵבֶר פָּנִים יָפוֹת:
Beth Shammai say: Make your Torah primary [i.e., let your principal endeavor, day and night, be in Torah. And when you tire from learning engage in some occupation; and do not make your occupation primary and your learning secondary. [I have found it written: "Make your Torah consistent. Do not be stringent (in ruling) for yourself and lenient for others, or stringent for others and lenient for yourself. But make your Torah consistent — for yourself as for others. And thus is it written in Ezra (7:10): 'For Ezra set his heart to expound the Torah of the L rd and to do and to teach the children of Israel' — just as he set his heart to do, so did he teach the children of Israel (to do).], say little and do much, [as we find with our father Abraham, of blessed memory, who first said (Genesis 18:5): "I will take a loaf of bread," and then (Ibid. 7): "And he took a calf, tender and good."], and receive all men with a kindly countenance. [When you invite guests to your house, do not receive them with your face "sunk in the ground," for if one does so, even if he bestowed upon them all the gifts in the world, it is accounted to him as if he gave them nothing. Shammai adduces three exhortations relating (respectively) to the three eminences mentioned by Jeremiah (9:22): wisdom, strength and wealth. Relative to wisdom he says: "Make your wisdom primary"; relative to wealth, "Say little and do much"; and relative to strength, "Receive all men with a kindly countenance. That is, one should suppress his inclination not to give and wage war with his recalcitrant heart. And we learned: "Who is strong? One who suppresses his (evil) inclination.]