"Again, you have heard that it was said to the people long ago, 'Do not break your oath,1 but keep the oaths you have made to the Lord.'2
References for Matthew 5:33
But I tell you, Do not swear at all:3 either by heaven, for it is God's throne;4
References for Matthew 5:34
or by the earth, for it is his footstool; or by Jerusalem, for it is the city of the Great King.5
References for Matthew 5:35
And do not swear by your head, for you cannot make even one hair white or black.