Shemayah and Avtalyon received from them. Shemayah says, "Love work": So that a man not be idle from work, since idleness brings a person to ennui (feeling unfulfilled and unhappy because you aren't being productive) (Ketuvot 59b); and that is a trait of illness, as it is stated about it (Proverbs 21:25), "The craving of a lazy man kills him, for his hands refuse to do." It means to say, when he accustoms his limbs to be idle from work, his hands refuse, since habit rules over them. And it also states about it (Proverbs 20:4), "From the winter the lazy man does not plow; at harvest time he seeks, and there is nothing." As he thinks when he is idle from work that it is rest for him, but it is the opposite; as [it is] with exertion [that] he will have rest. As with the winter he will rest and stay in his house and not plow and seek to reap and gather the grain [when] there is none and die of hunger. But the one who plows in the winter - 'he who tills his land will be sated with bread,' as a man cannot reach rest without exertion first. 'But he who pursues vanities' and pursues the ones that sit in the corners idle from work 'will be sated with poverty.'
"Love work": Even if he has from what to sustain himself, he is obligated to work, as idleness leads to feeling unfulfilled (Ketuvot 59b)
דְּהַשְׁתָּא אֵינוֹ עוֹשֶׂה הַמְּלָאכָה מִפְּנֵי שְׂכָרָהּ אֶלָּא לְאַהֲבָתָהּ בְּעַצְמָהּ. . . .
Since now he is not doing work for its reward but for its own love. . . .