Don't Take an Oath at All

“Again, you have heard that it was said to our ancestors, You must not break your oath, but you must keep your oaths to the Lord. But I tell you, don’t take an oath at all: either by heaven, because it is God’s throne; or by the earth, because it is His footstool; or by Jerusalem, because it is the city of the great King. Neither should you swear by your head, because you cannot make a single hair white or black. But let your word ‘yes’ be ‘yes,’ and your ‘no’ be ‘no.’ Anything more than this is from the evil one." -Matt 5: 33-39