Commentary on Matthew 5:33-37
Sermon on the Mount (cont’d):
Today’s third example of Jesus’ “filling out” the meaning of the Law is based on the instruction, “You must not break your oath, but must fulfil your oaths to the Lord.” In the book of Numbers we read: “If a man makes a vow to Yahweh or takes a formal pledge under oath, he must not break his word: whatever he promises by word of mouth he must do” (Numbers 3:30).
Jesus goes far beyond this requirement. He simply tells us to stop making oaths altogether. The true follower of Christ does not need to take oaths or to swear on anything, however sacred, to guarantee the truth of his words. “All you need say is ‘Yes’ if you mean ‘Yes’, ‘No’ if you mean ‘No’.”
The Christian should be a person of known integrity. He can be taken at his word and no further guarantee is required. It is nice to be known as such a person. Truth should be our second name.
Sometimes, of course, people may not be entitled to the whole truth. In fact, honour may require us even to sacrifice our life rather than reveal something that might put another person in danger but we should never be guilty of positively deceiving another.