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.
it was said (v.33) — Exodus 20:17; Leviticus 19:12; Numbers 30; Deuteronomy 23:21
Many of my commentaries were very brief, leading me to believe the writers weren’t quite sure of what to make of this section. Others pointed out the fact that the Lord Himself answered when put on oath before the High Priest, that God confirmed His promise with an oath in Hebrews 6:17 and that Paul make many of his statements with oaths (i.e., Galatians 1:20; 2 Timothy 2:14, etc.). Therefore, they say, the Lord in Matthew 5 was simply pointing out the importance of being a man of your word so that people will trust you and not demand your oath and that you should only give oaths in important matters, not in casual conversation. Some see it as a contrast with the Pharisees who frequently got carried away with their oaths. Gaebelein makes sense when he applies it to the kingdom when believers will tell the truth because the law will be written on their hearts. I’m not sure exactly where I fall, although most of what I just wrote seems applicable.
Every oath contained an affirmation of promise of an appeal to God as the omniscient punisher of falsehoods, which made an oath binding. By the time of Christ, the Jews had developed an elaborate system of oath-taking, which often formed the basis of actual lying. For example, one might swear that he had told the truth according to the dome of the Temple, while another might swear by the gold on the dome of the Temple! In other words, there were stages of truth and thus also of falsehood within the system of taking oaths. — King James Bible Commentary, page 1180
Since Christ allowed Himself to be put under an oath (Matthew 26:63-64), we conclude that He did not forbid His hearers to put themselves under an oath. He was telling them that their character, reputation for honesty, and word should be so true, undefiled, and without duplicity that no one would think it necessary to put them under an oath, for no one would suspect them of deception. When the Pharisees took an oath, they affirmed something that could be understood in more than one way. They had mental reservations about what they were affirming. Christ told His listeners that when they made a statement, they should let their yes be yes and their no be no. Yes cannot mean no, and no cannot mean yes (cf. 2 Corinthians 1:17-20). These words are not open to several interpretations. Believers should affirm only what is true. — Pentecost, page 180
Except that the Lord DOES tell them not to swear oaths and that if they do it is of Satan …
There’s something in what Gaebelein says (below) but I’m not sure what …
Significant here is the description of Jerusalem as the city of the great King. This will be during the millennial reign. When the kingdom has come praise will be heard in the heavens, in the earth and in Jerusalem. Now the earth is full of swearing and wicked words, but in that coming day the offences will be gathered out of the kingdom. — Gaebelein, page 129