Do not add anything to his words, lest you be reproved and be discovered to be a liar
Other versions
King James Version
Add thou not unto his words, lest he reprove thee, and thou be found a liar.English Standard Version
Do not add to his words, lest he rebuke you and you be found a liar.New International Version
Do not add to his words, or he will rebuke you and prove you a liar.