How to reconcile Matthew 5:19 and Matthew 5:34 and Numbers 30:2 on the issue of swearing oaths?

Question

Numbers 30:

2 If a man makes a vow to the LORD or swears an oath to obligate himself by a pledge, he must not break his word; he must do everything he has promised.

Matthew 5:

33“Again, you have heard that it was said to the people long ago, ‘Do not break your oath, but fulfill to the Lord the vows you have made.’

Apparently, Jesus alluded to Moses.

34 But I tell you, do not swear an oath at all: either by heaven, for it is God’s throne;

Apparently, Jesus contrasted Moses. But some verses earlier, he said:

19 Therefore anyone who sets aside one of the least of these commands and teaches others accordingly will be called least in the kingdom of heaven, but whoever practices and teaches these commands will be called great in the kingdom of heaven.

Was Jesus setting Number 30:2 aside to promote Matthew 5:34?

Related question:

Did Paul contradict Christ in Acts 18:18 taking the Nazarite vow; Matt 5:34 "take no oath at all"?

My question is not about whether it is okay to swear or not.

Answer 1

Consider:

• Father says: “If you borrow money, make sure you repay it as soon as you can.”
• Mother says: “Don't borrow money.”

The second advice doesn't set aside the first, negate it, or even imply that it isn't good advice.
It simply encourages one to be in a position where the "if" condition won't apply.

Similarly "Don't lust in your heart" doesn't set aside the prohibition on adultery.

Answer 2

Was Jesus setting Numbers 30:2 aside to promote Matthew 5:34?

Answer: Yes.

This question relates directly to the distinction between the Law of Moses (which has been "set aside") and the Law of Christ. We can know this when we consider the Letter to the Hebrews:

Hebrews 7:11-12: "Now if perfection was through the Levitical priesthood (for on the basis of it the people received the Law), what further need was there for another priest to arise according to the order of Melchizedek, and not be designated according to the order of Aaron? ¹²For when the priesthood is changed, of necessity there takes place a change of law also."

Here is another instance where we can know that many of the laws of the O/T, such as making vows, have been done away (or revised) in Christ:

Galatians 3:23-24a: "But before faith came, we were kept in custody under the law [of Moses], being shut up to the faith which was later to be revealed [in Christ]. Therefore the Law [of Moses] has become our tutor to lead us to Christ..."

These passages are emblematic of the distinction between the Law of Moses (the Old Covenant) and the Law of Christ (the New Covenant) — Christ being our High Priest. Not only was the priesthood changed but so too was the entire Mosaic system upon which all else rested. Some may disagree with this observation, instead choosing to believe that the change was minor.

Nonetheless, the Mosaic order was reinstituted in another form upon the inauguration of the new priesthood, one in which all Christians (saints) partake as priests (cf. 1 Pet. 2:9, and a temple: 1 Cor. 6:19).

As pointed out in the OP, this is particularly significant based on Jesus' Sermon on the Mount, in which He repeatedly enumerated many of the O/T laws beginning with "You have heard it said..." while replacing them with His new, more stringent commands (paraphrased):

"You have heard it said":

1. "You shall not commit murder, but he who hates his brother has committed murdered in his heart" (Matt. 5:21-22).
2. "You shall not commit adultery, but he who lusts in his heart has committed adultery..." (Matt. 5:27-28).
3. "He who divorces his wife and marries another commits adultery" (Matt. 5:31-32).
4. "You shall make no false vows... But I say make no oath at all" (Matt. 5:33-37).
5. "An eye for an eye... turn the other cheek" (Matt. 5:38-39).
6. "You shall love your neighbor and hate your enemy... love your enemies, pray for those who persecute you" (Matt. 5:43-44).

With regard to Matthew 5:19 from the OP, Coffman had the following to say:

In this verse, Christ plainly refers to his own commandments with the strong warning that men are under obligations to heed and observe the laws he gives. Today, there are some who speak of certain Scriptures as "mere command". But Christ made his commandments to be of overwhelming importance and set forth the principle that "the least" of his commandments was to be received and honored with [respect] and obedience (emphasis added).

The 613 laws and ordinances under the Mosaic regime have been superseded by a stricter set of laws that comprise the Law of Christ (Gal. 6:2), or the Law of Liberty (Jas. 1:25, 2:12), or the Royal Law (Jas. 2:8): there are other equivalent designations of the perfect Law of Christ (Jas. 1:25).

Christ nailed the Law of Moses to the Cross (Col. 2:14), by introducing His Own commandments (only a few of which are listed above). The new laws are far more comprehensive than anything written in the Old Testament because they apply to our thoughts as well as our actions.

A passage in the Letter of James appears to settle the matter regarding vows:

James 5:12: "But above all, my brethren, do not swear, either by heaven or by earth or with any other oath; but your yes is to be yes, and your no, no, so that you may not fall under judgment." (cf. Matt. 5:37).

Yes, Christ has "set aside" the Law of Moses where there has indeed been a change in the Law — and that includes making vows.

Answer 3

The following Bible scholars summarize Matt. 5:33-37 as based on perjury. That makes sense of v37 to simply say yes or no truthfully.

Kaiser, W. C., Jr., Davids, P. H., Bruce, F. F., & Brauch, M. T. (1996). Hard sayings of the Bible (pp. 361–362). Downers Grove, IL: InterVarsity.

5:34 Do Not Swear at All?

1. The first related commandment was to not take the LORD's name in vain.

Perjury is a serious offence in any law code. It was so in the law of Moses and is forbidden in the third commandment: “You shall not take the name of the Lord your God in vain; for the Lord will not hold him guiltless who takes his name in vain” (Ex 20:7 RSV).

2. Then was the prohibition not to swear an oath falsely.

To swear an oath falsely in the name of God was a sin not only against the name but against the very person of God. Later the scope of the commandment was broadened to include any light or thoughtless use of the divine name, to the point where it was judged safest not to use it at all. That is why the name of the God of Israel, commonly spelt Yahweh, came to be called the ineffable name, because it was forbidden to pronounce it. The public reader in the synagogue, coming on this name in the Scripture lesson, put some other form in its place, lest he should “take the name of the Lord [his] God in vain” by saying “Yahweh” aloud. But originally it was perjury that was in view in the commandment, and in other injunctions to the same effect from Exodus to Deuteronomy. Summing up the sense of those injunctions, Jesus said, “You have heard that it was said to the people long ago, ‘Do not break your oaths, but keep the oaths you have made to the Lord’” (Mt 5:33).

3. When swearing people replaced the name of God for something else.

Realizing the seriousness of swearing by God if the truth of the statement was not absolutely sure, people tended to replace the name of God by something else—by heaven, for example—with the idea that a slight deviation from the truth would then be less unpardonable. From another passage in this Gospel (Mt 23:16–22) it may be gathered that there were some casuists who ruled that vows were more binding or less binding according to the precise wording of the oath by which they were sworn. This, of course, would be ethical trifling.

4. Jesus set a higher standard.

It was necessary that people should be forbidden to swear falsely, whether in the name of God or by any other form of words. “Fulfill your vow,” says the Preacher whose practical maxims enrich the Old Testament Wisdom literature; “It is better not to vow than to make a vow and not fulfill it” (Eccles 5:4–5). But Jesus recommends a higher standard to his disciples. “Do not swear at all,” he says; “Simply let your ‘Yes’ be ‘Yes,’ and your ‘No,’ ‘No’; anything beyond this comes from the evil one” (Mt 5:37). An echo of these words is heard in a later book of the New Testament: “Above all, my brothers, do not swear—not by heaven or by earth or by anything else. Let your ‘Yes’ be yes, and your ‘No,’ no, or you will be condemned” (Jas 5:12).

5. Christians should be known for keeping their word.

The followers of Jesus should be known as men and women of their word. If they are known to have a scrupulous regard for truth, then what they say will be accepted without the support of any oath. This is not mere theory; it is well established in experience. One body of Jesus’ followers, the Society of Friends, has persisted in applying these words of his literally. And such is their reputation for probity that most people would more readily trust the bare word of a Friend than the sworn oath of many another person. “Anything beyond this,” said Jesus, “comes from the evil one”; that is to say, the idea that a man or woman can be trusted to speak the truth only when under oath (if then) springs from dishonesty and suspicion, and tends to weaken mutual confidence in the exchanges of everyday life. No one demands an oath from those whose word is known to be their bond; even a solemn oath on the lips of others tends to be taken with a grain of salt.

Answer 4

Was Jesus setting Number 30:2 aside to promote Matthew 5:34?

No Jesus was not setting Number 30:2 aside.

Yes, Jesus was promoting Matthew 5:34.

Paul swears.

2 Corinthians 1:23 I call God as my witness that it was in order to spare you that I did not return to Corinth.

Answer 5

How to reconcile Matthew 5:19 and Matthew 5:34 and Numbers 30:2 on the issue of swearing oaths?

Matthew chapter 5 is the beginning of Jesus' well-known Sermon on the Mount. Near the beginning of this Sermon, he clearly states in verse 17 “Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them." (NIV)

So here Jesus establishes that he is not denying or saying anything against the Mosaic Law. In verse 19, Jesus emphasizes the need to keep and obey the Mosaic Law.

Was Jesus setting Number 30:2 aside to promote Matthew 5:34?

Jesus was actually "calling out" the religious leaders of his day for making frivolous oaths or vows. The topic "Oath" in the Insight on the Scriptures details what Jesus meant:

Jesus Christ, in his Sermon on the Mount, corrected the Jews in their practice of light, loose, and indiscriminate making of oaths. It had become common among them to swear by heaven, by the earth, by Jerusalem, and even by their own heads. But since heaven was “God’s throne,” earth his “footstool,” Jerusalem his kingly city, and one’s head (or life) was dependent on God, making such oaths was the same as taking oaths in the name of God. It was not to be treated lightly. So Jesus said: “Just let your word Yes mean Yes, your No, No; for what is in excess of these is from the wicked one.”​—Mt 5:33-37.

Jesus Christ did not hereby prohibit the making of all oaths, for he himself was under the Law of Moses, which required oaths under certain circumstances. In fact, when Jesus himself was on trial he was put under oath by the high priest, yet he did not object to this, but gave an answer. (Mt 26:63, 64) Rather, Jesus was showing that a person should not have two standards. The keeping of one’s word, once given, should be viewed as a sacred duty and should be fulfilled just as an oath would be; the person should sincerely mean what he says. He shed further light on the meaning of his words when he exposed the hypocrisy of the scribes and Pharisees by saying to them: “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 under obligation.’ Fools and blind ones! Which, in fact, is greater, the gold or the temple that has sanctified the gold?” He went on to say: “He that swears by heaven is swearing by the throne of God and by him that is sitting on it.”​—Mt 23:16-22.

By the false reasoning and hairsplitting casuistry of these scribes and Pharisees, as here pointed out by Jesus, they justified themselves in failing to carry out certain oaths, but Jesus showed that such swearing on their part was being dishonest with God and was actually reproaching his name (for the Jews were a people dedicated to Jehovah). Jehovah plainly states that he hates a false oath.​—Zec 8:17. [bold mine]

We should keep in mind that Jehovah gave Moses a set of law that needed to be followed. But they were laws, a set of rules that basically stated do's and don'ts.
Jesus, on the other hand, showed the principle behind the Mosaic Law so that the individual would follow Jehovah's commandments from their heart and not by rote.

[Unless otherwise noted, all scripture quotations from the New World Translation of the Holy Scriptures (Study Edition)]