Mishnayos Avos Perek 1 Mishnah 15

”Make your Torah fixed”: such that your main occupation during the day and the night be Torah [study] and when you are weary from study, do work. And not that your main occupation be work and when you are free from work, you involve yourself in Torah. And I have found it written, “'Make your Torah fixed' such that you are not strict on yourself and lenient on others or strict on others and lenient on yourself, but [rather] your Torah should be fixed, for yourself like for others. And so is it stated in Ezra 7:10, 'Since Ezra prepared his heart to expound the Torah of the Lord and to do [it] and to teach the Children of Israel; as he prepared his heart to do, so too did he teach the Children of Israel.'"

”say little and do much”: as we find by Avraham, our father, peace be upon him, who first said (Genesis 18), “and I will get a morsel of bread,” and in the end, “and he took a tender and good young cow."

"and receive every person with a pleasant countenance": When you bring in guests to your home, do not give to them while 'your face is buried in the ground;' as anyone who gives and 'his face is buried in the ground' - even if he gave all of the gifts in the world - it is counted for him as if he did not give anything. Shammai gave three warnings, corresponding to three virtues that Yirmiyahu mentioned: wise, strong and wealthy. Corresponding to wise, he said, ”Make your Torah fixed;” corresponding to wealthy, he said, ”say little and do much;” and corresponding to strong, he said, "receive every person with a pleasant countenance" - that he should conquer his inclination [to do bad] and fight against his wicked heart. And we have learned, "Who is a mighty one? The one who conquers his inclination."