Matthew 5:34-37

But I tell you, Do not bind yourselves by an oath at all: either by heaven, for it is the throne of God; Or by the earth, for it is the footstool of His feet; or by Jerusalem, for it is the city of the Great King. [Ps. 48:2; Isa. 66:1.] And do not swear by your head, for you are not able to make a single hair white or black. Let your Yes be simply Yes, and your No be simply No; anything more than that comes from the evil one. [Lev. 19:12; Num. 30:2; Deut. 23:21.]