We come again to another text within the Sermon on the Mount where Jesus is addressing how the teachers of the Law and the Pharisees were incorrectly teaching and misapplying the Law of Moses. As we have seen so far in our study, Jesus is correcting these errors and showing the heart needed to be God’s people as well as identifying the high standard of God’s law.
Again you have heard that it was said to those of old, “You shall not swear falsely, but shall perform to the Lord what you have sworn.” (Matthew 5:33 ESV)
Jesus quotes what the teachers are saying the Law declared. In this case it appears that they are quoting the Law fairly accurately.
You shall not swear by my name falsely, and so profane the name of your God: I am the Lord. (Leviticus 19:12 ESV)
If a man vows a vow to the Lord, or swears an oath to bind himself by a pledge, he shall not break his word. He shall do according to all that proceeds out of his mouth. (Numbers 30:2 ESV)
Further, we need to note that the Law did instruct the people to make vows and oaths by the name of the Lord. We see this in the above passages just read (Leviticus 19:12; Numbers 30:2). The condemnation was not against taking oaths, but that they must not make a false oath or break their oaths. This is confirmed in the Law as read in Deuteronomy 10:20.
You shall fear the Lord your God. You shall serve him and hold fast to him, and by his name you shall swear. (Deuteronomy 10:20 ESV)
But when we read Matthew 5:34-36 we are able to get a sense of what the people were doing and the Pharisees were teaching. Notice that they were taking oaths by all of these other things rather than the name of the Lord. They would make an oath by heaven, by earth, by Jerusalem, by their head, and the like. When we read the Jewish teachings it becomes even clearer what was happening. Notice the writing from the Mishnah, which is the collection of historical rabbinical teachings.
m. Sebu. 4.13: If a man said, “I adjure you” or “I command you” or “I bind you,” they are liable; but if he said “By heaven and earth,” they are exempt.
m. Ned. 1.3: If he says, “May it be by Jerusalem,” he has said naught.
m. Sanh. 3.2: If a man take an oath before his fellow, and his fellow said to him, “Vow to me by the life of your head,” R. Meir says he may retract.
Rabbi Maimonides: If any swear by heaven, by earth, by the sun, etc although the mind of the swearer be under these words to swear by Him who created them, yet this is not an oath. Or is any swear by some of the prophets, or by some of the books of the Scripture, although the sense of the swearer be to swear by Him that sent that prophet or that gave that book, nevertheless this is not an oath. Later Jewish commentary argued that a vow made “by” Jerusalem was nonbonding but a vow made “toward” Jerusalem was binding (t. Ned. 1.2.3). By contrast, Josephus says of the Essenes who were rigorous about avoiding oaths: “Any word of theirs has more force than an oath, swearing they avoid, regarding it as worse than perjury, for they say that one who is not believed without an appeal to God stands condemned already” (Jewish War 2.135). Jesus gives us even more clarity on the problem later on in the Gospel of Matthew.
Woe to you, blind guides, who say, “If anyone swears by the temple, it is nothing, but if anyone swears by the gold of the temple, he is bound by his oath.” You blind fools! For which is greater, the gold or the temple that has made the gold sacred? And you say, “If anyone swears by the altar, it is nothing, but if anyone swears by the gift that is on the altar, he is bound by his oath.” You blind men! For which is greater, the gift or the altar that makes the gift sacred? So whoever swears by the altar swears by it and by everything on it. And whoever swears by the temple swears by it and by him who dwells in it. And whoever swears by heaven swears by the throne of God and by him who sits upon it. (Matthew 23:16–22 ESV)
Now we are able to understand what is happening in the first century. They read the command in Leviticus 19:12 and Numbers 30:2 to mean that if you made your oath to the Lord, then you must keep what you have vowed. But, if you made your oath on the basis of something else or someone else, then you did not make your vow to the Lord and your word could be broken. Do you remember when you were kids and you or your friends would make some solemn promise to you about what they were about to do and then later on they would say that they had their fingers crossed? As kids we thought having our fingers crossed meant that we were exempt from whatever we were promising. In the same way, if these vows were made by something other than the name of the Lord, then you were allowed to break the oath.
This is what Jesus is observing and condemning in Matthew 5:34-36. Do not take an oath by heaven as if that will relinquish your need to keep what you vow because heaven is the throne of God. Do not take an oath by earth because earth is the footstool of God. Do not take an oath by Jerusalem because it is the city of the great King. Do not take an oath by your head because you cannot make your hair white or black. Do not make oaths like this as if this gives you a way out of your vow in the future. Everything belongs to God. Heaven and earth belong to God. Jerusalem belongs to God. The hairs on your head belong to God. You are not able to get our of your promise just because you did not swear by the name of the Lord. Everything is God’s and therefore every oath is binding. There is nothing you can take an oath by or some action you can take like crossing your fingers that allows you to violate what was promised.
Declaring God’s Law (5:37)
This brings us to what God was actually teaching. God’s people are to be truthful and honest. God hates deception (Proverbs 6:17; 12:22). The purpose of an oath was to guarantee that the promise would be fulfilled. The Jews were using oaths as a means of avoiding what was promised! They were taking oaths to get out of what they were saying. God’s people are to have speech that is straightforward. Every word we utter is before God and subject to judgment (Matthew 12:36-37). A simple yes or no puts us under no less obligation to tell the truth and honor it than taking an oath. Oaths were never intended to heighten the swearer’s obligation to tell the truth. That obligation already existed when the words left your mouth. Rather, oaths were intended to give greater assurance to those who receive the promise. Please consider that this is exactly what God did.
For when God made a promise to Abraham, since he had no one greater by whom to swear, he swore by himself, saying, “Surely I will bless you and multiply you.” And thus Abraham, having patiently waited, obtained the promise. For people swear by something greater than themselves, and in all their disputes an oath is final for confirmation. So when God desired to show more convincingly to the heirs of the promise the unchangeable character of his purpose, he guaranteed it with an oath, so that by two unchangeable things, in which it is impossible for God to lie, we who have fled for refuge might have strong encouragement to hold fast to the hope set before us. (Hebrews 6:13–18 ESV)
Why did God swear by himself when he made the promise to Abraham? Was it so that God would now have to be bound to his word? No, for once God says anything he is bound to his word. The purpose of the oath was that “God desired to show more convincingly to the heirs of the promise the unchangeable character of his purpose.” The purpose of the promise is to give greater assurance to the recipient of the promise. This is why we read about God making oaths to his people (cf. Luke 1:73; Acts 2:30). God is convincing us by what he says.
This is the point Jesus is making. Your word is always binding. Your “yes” must be “yes,” and your “no” must be “no.” We do not get to avoid our obligations simply because we did not make an oath before God. Please do not misunderstand what Jesus is saying. When Jesus says, “Do not take an oath at all” and when James says the same in James 5:12, the point is not to say that making an oath is a sin. We should understand this because God made oaths and we see his people rightly making oaths in the scriptures. Jesus’ point is that when you say “yes” it is just as binding as if you took an oath. You do not say something thinking that if you say it is a particular way that you are freed from your obligation. You are bound by your word.
This should solve the question about whether a Christian can make an oath today. In a court of law a Christian can and must take an oath and this is right to do because you are declaring the veracity of your words before people. Remember, the purpose of an oath is to give greater assurance to the recipient. We have every need to do this for people in a world that is full of liars and deceivers. But Jesus’ greater point is that just because you did not take an oath does not mean you are not bound to your word. When Jesus says, “Do not take an oath at all,” we must read the rest of verse 34. Jesus is saying do not take oaths like that because the reason they took such an oath what to give themselves a backdoor option to not keeping their promise. Have the character that when you tell someone you will do something, they believe you. We should not have to convince people who know us about our truthfulness. We will always be honest and truthful. But for those who do not know us, like in a court situation, make your oath to God to give greater assurance to those who listen concerning what you are about to say.