Sefer Chasidim Siman 119
Can copy this into an AI, or connect the whole library to your assistant. For deeper learning, you can directly use the original seforim, sites, and apps.
יש גוזל ואינו נראה זה הדר עם בני אדם ועינו רעה בשלהם:
Medieval Jewish mysticism, translated by Sholom Alchanan Singer. Northbrook, Ill. Whitehall Co., 1971
There is one who steals and is not seen. It is the person who lives with other people and begrudges them that which is theirs.¹
footnotes: ¹ Erubin 65a.