The Commands of Jesus: Do not swear an oath at all…
Jesus begins by summing up a teaching from the OT about swearing by oaths and/or taking vows in the name of the Lord. There are several teachings in the OT about swearing by oaths and taking vows.
Lev. 19.12 - Do not swear falsely by my name and so profane the name of your God. I am the LORD.
That is, if you swear by the name of the Lord, keep your oath.
Num. 30.2 - When a man makes a vow to the LORD or takes an oath to obligate himself by a pledge, he must not break his word but must do everything he said.
Deut. 23.21-23 - If you make a vow to the LORD your God, do not be slow to pay it, for the LORD your God will certainly demand it of you and you will be guilty of sin. But if you refrain from making a vow, you will not be guilty. Whatever your lips utter you must be sure to do, because you made your vow freely to the LORD your God with your own mouth.
Thus, you can see that an oath or a vow was a very serious, sacred thing. In fact, this is probably what one of the Ten Commandments was talking about (taking the Lord’s name in vain).
What would cause someone to take an oath or make a vow? There are various reasons, such as in judicial situations. But there were other situations that may prompt someone to take a vow.
Jacob made a vow to God that if He performed an act for Jacob, he would serve him.
Gen. 28.20-21 - Then Jacob made a vow, saying, “If God will be with me and will watch over me on this journey I am taking and will give me food to eat and clothes to wear so that I return safely to my father’s household, then the LORD will be my God
David made an oath that he would not rest until he found a dwelling place for the Ark of the Covenant (Psalm 132.1-3).
The people of Israel made a vow that if God would deliver some of their people who had been captured by a foreign king, they would utterly destroy those people (Num. 21.1-3).
One of the Proverbs talks about the importance of fulfilling your vows and oaths.
Prov. 20:25 - It is a trap to dedicate something rashly and only later to consider one’s vows.
Some examples of vows that were not well thought out:
Judges 11.30-31 - Jephthah made a vow to the LORD: “If you give the Ammonites into my hands, whatever comes out of the door of my house to meet me when I return in triumph from the Ammonites will be the LORD’s, and I will sacrifice it as a burnt offering.”
The result: verses 34-35 - When Jephthah returned to his home in Mizpah, who should come out to meet him but his daughter, dancing to the sound of timbrels! She was an only child. Except for her he had neither son nor daughter. When he saw her, he tore his clothes and cried, “Oh no, my daughter! You have brought me down and I am devastated. I have made a vow to the LORD that I cannot break.”
Herod Antipas, when pleased by the dance of young Salome:
Mark 6:22-25 - The king said to the girl, “Ask me for anything you want, and I’ll give it to you.” And he promised her with an oath, “Whatever you ask I will give you, up to half my kingdom.”… At once the girl hurried in to the king with the request: “I want you to give me right now the head of John the Baptist on a platter.”
The example of a good vow? Hannah and Samuel (1 Samuel 1:10-11).
Why would people make such vows? Often they did so in order to strengthen their resolve to act on a matter. They knew that if they invoked God’s name in front of witnesses, knowing how serious oaths were, they would move heaven and earth to keep their oath or fulfill their vow.
Notice the names invoked when Jesus discusses oaths: heaven, earth, Jerusalem, your head. It seems that, again, religious people were finding ways around the Law. Some people felt that they could get around keeping a vow if they vowed by heaven or by Jerusalem instead of invoking God’s name. They might be serious about keeping a vow, but maybe not that confident. Jesus shows them how silly this is. You still invoke God in your oath in the name of heaven, because Heaven is God’s throne. You still invoke God in your oath in the name of the earth, because the earth is God’s footstool (Isaiah 61.1). If you swear by your own head, you speak against God sovereignty. He is the one who holds the future to your life.
When it comes right down to it, Jesus tells us that oaths and vows are unnecessary. All we need to do is keep our word. Let our yes be our yes. Let our no be our no.
Do you find yourself saying “I promise” after you say you are going to do something? Why? Is it habit? Is it insecurity (you don’t think people believe you)? Is it your past? Do people doubt your word so you feel like you must reinforce your statements with several “I promise” or “I swears”?
Our words should not be frivolous. Especially statements of things we are going to do. We need to be serious in keeping our word. We need to be people that when we say we are going to do something or be somewhere, people know that is what we are going to do and where we will be.
James 5:12 echoes these words of Jesus as well: Above all, my brothers and sisters, do not swear—not by heaven or by earth or by anything else. All you need to say is a simple “Yes” or “No.” Otherwise you will be condemned.