251 – Negative Mitzvah 251 - Not to oppress one another with words – 251 - המצווה הרנ"א - האזהרה שהזהרנו מלהונות זה את זה בדברים

From Sefer Hamitzvos Daily study - Rabbi Chaim Wolosow by R Chaim Wolosow.

This mitzvah is the prohibition against wronging another person with words (ona'as devarim) — saying things that pain or shame him, such as reminding a baal teshuvah of his past. It is learned from "You shall not wrong one another, and you shall fear your G-d" (Vayikra 25:17), and is graver than wronging in money.

https://www.torahrecordings.com/rambam_sefer_hamitzvos/002/251