But let your word be: Yes, yes, and No, no. And anything more than this is from evil.
With these words Jesus sums up the teaching about oaths, teaching that the speech of a truthful person must be simple, clear, and honest, without unnecessary swearing or exaggeration. The expression “Yes means yes, and No means no” means that one’s words must reflect the true intention of the heart, because every excessive emphasis or formal confirmation is born from distrust and violates the purity of speech. With the phrase “Anything beyond this is from evil,” he warns that when a person tries to give force to his words with oaths or other guarantees, his speech loses its spiritual dignity, and suspicion toward his words begins, and therefore the influence of evil begins to operate. Thus, Jesus affirms the new law: complete purity and sincerity of speech, where the promise is equal to the deed that is done.