34 But I say unto you, Do not swear at all; neither by the heaven, because it is [the] throne of God; 35 nor by the earth, because it is [the] footstool of his feet; nor by Jerusalem, because it is [the] city of the great King. 36 Neither shalt thou swear by thy head, because thou canst not make one hair white or black.
Matthew Henry's Commentary on Matthew 5:34-36
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.