matthew 5:37 But let your communication be, Yea, yea; Nay, nay: for whatsoever is more than these cometh of evil. - Free Bible Online

      37. But let your communication--"your word," in ordinary intercourse, be,
      Yea, yea; Nay, nay--Let a simple Yes and No suffice in affirming the truth or the untruth of anything. (See Jas 5:12; 2Co 1:17, 18).
      for whatsoever is more than these cometh of evil--not "of the evil one"; though an equally correct rendering of the words, and one which some expositors prefer. It is true that all evil in our world is originally of the devil, that it forms a kingdom at the head of which he sits, and that, in every manifestation of it he has an active part. But any reference to this here seems unnatural, and the allusion to this passage in the Epistle of James (Jas 5:12) seems to show that this is not the sense of it: "Let your yea be yea; and your nay, nay; lest ye fall into condemnation." The untruthfulness of our corrupt nature shows itself not only in the tendency to deviate from the strict truth, but in the disposition to suspect others of doing the same; and as this is not diminished, but rather aggravated, by the habit of confirming what we say by an oath, we thus run the risk of having all reverence for God's holy name, and even for strict truth, destroyed in our hearts, and so "fall into condemnation." The practice of going beyond Yes and No in affirmations and denials--as if our word for it were not enough, and we expected others to question it--springs from that vicious root of untruthfulness which is only aggravated by the very effort to clear ourselves of the suspicion of it. And just as swearing to the truth of what we say begets the disposition it is designed to remove, so the love and reign of truth in the breasts of Christ's disciples reveals itself so plainly even to those who themselves cannot be trusted, that their simple Yes and No come soon to be more relied on than the most solemn asseverations of others. Thus does the grace of our Lord Jesus Christ, like a tree cast into the bitter waters of human corruption, heal and sweeten them.

JFB.