Albert Barnes Commentary Proverbs 30:10

"Slander not a servant unto his master, Lest he curse thee, and thou be held guilty." — Proverbs 30:10 (ASV)

Accuse not a servant - The prayer in (Proverbs 30:8) does not shut out sympathy with those who are less favored. Even the slave has a right to protection against frivolous or needless accusation. Others, however, render the words Make not a slave to accuse his master, that is, do not make him discontented with his lot, lest he afterward curse you for having made it worse than it was.