34 But I say to you, Take no oaths at all: not by the heaven, because it is the seat of God; 35 Or by the earth, because it is the resting-place for his foot; or by Jerusalem, because it is the town of the great King. 36 You may not take an oath by your head, because you are not able to make one hair white or black. 37 But let your words be simply, Yes or No: and whatever is more than these is of the Evil One.
Matthew Henry's Commentary on Matthew 5:34-37
Commentary on Matthew 5:33-37
(Read Matthew 5:33-37)
There is no reason to consider that solemn oaths in a court of justice, or on other proper occasions, are wrong, provided they are taken with due reverence. But all oaths taken without necessity, or in common conversation, must be sinful, as well as all those expressions which are appeals to God, though persons think thereby to evade the guilt of swearing. The worse men are, the less they are bound by oaths; the better they are, the less there is need for them. Our Lord does not enjoin the precise terms wherein we are to affirm or deny, but such a constant regard to truth as would render oaths unnecessary.