Halakhah su Salmi 37:16

The good and right path to follow is to accustom yourself to walk the middle course. You should desire only those things which are required for your physical well being, and without which it is impossible to live, as it is written, "The righteous person eats to satisfy his soul."²Proverbs 13:25. “To satisfy his soul” means “to keep his soul alive”, in other words he eats no more than is needed to sustain life, certainly no gourmet foods. (Malbim) You should be absorbed in your business affairs only to the extent that it enables you to acquire things that you need for your daily life, as it is written, "Better is the little of the righteous."³Psalms 37:16. Do not be overly tight-fisted, nor spend your money too freely, but rather give charity according to your ability and lend money wisely to whom ever needs it. Do not be too jubilant and jolly, nor too sad and gloomy. But be happy at all times, be contented and show a friendly face. And so too with most other character traits, anyone who follows the middle course is called a wise man.