Matthew 5:33 – 37

33 “Again you have heard that it was said to those of old, ‘You shall not swear falsely, but shall perform your oaths to the Lord.’

34 But I say to you, do not swear at all: neither by heaven, for it is God’s throne;

35 nor by the earth, for it is His footstool; nor by Jerusalem, for it is the city of the great King.

36 Nor shall you swear by your head, because you cannot make one hair white or black.

37 But let your ‘Yes’ be ‘Yes,’ and your ‘No,’ ‘No.’ For whatever is more than these is from the evil one.

Jesus is speaking of promises we make to God and man, verse 33 particularly refer to false promises made to God, He refers to (Leviticus 19:12) where false oaths were expressly forbidden, this is going to be another example of the difference between the old law and the new law.

Verse 34 is going to show, under the new law, whether the oath is true or false, Jesus forbids his followers of making them.

The difference between a promise and an oath is an oath is made when a person backs it up with some authority which is great enough to verify the oath as being true. As examples He uses things such as “by heavens” or “by earth” or “by Jerusalem”

The Jewish people knew it was wrong to swear by the name of God, but Jesus shows it is wrong to swear by “heaven” because it is the throne of God.

“by earth” because it is God's footstool.

“by Jerusalem” because it was the city of God.

If you cannot swear by God and His things, what about swearing by man and his things, Jesus says in verse 36 that man does not have the power to swear by. By our own power we do not have the strength to change nature. Don't swear by your head because you cannot change the color of your hair, sure you can use chemicals to color it, but given time it returns to its natural color.

Just use the words yes or no, there is none other needed, if you are promising to God or man, your word is either true or false. A simple yes or no is the true answer, don't make false promises and don't swear by anything, just say yes or no.