Sefer Ha’mitzvos Ha’Katzar (The concise book of mitzvos) By the Chofetz Chaim
This book lists the Torah mitzvos that can be observed today
Second Section – the Negative Commandments
48. It is a negative commandment “Do not hurt one’s friend with words.”
As it states in Vayikra (Leviticus) 25:17, “and a man shall not wrong another.” This means, a person should not say to a person who repented from his previously sins, “remember your old ways.” Nor should he say to a convert, “remember the ways of your father.” Nor should he ask a matter of wisdom from one who does not have wisdom, thereby hurting him. Anything like this is wronging with words.