Matthew 5:33-35

“Again, you have heard that it was said to the men of old, ‘YOU SHALL NOT MAKE FALSE VOWS, BUT YOU SHALL FULFILL YOUR VOWS TO THE LORD [as a religious duty].’ But I say to you, do not make 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; Is 66:1]