Subhāsitasutta

sn8.5:3.1 “Good people say well-spoken words are foremost;

sn8.5:3.2 second, speech ought be principled, not unprincipled;

sn8.5:3.3 third, speak pleasantly, not unpleasantly;

sn8.5:3.4 and fourth, speak truthfully, not falsely.”