9166. 'An oath of Jehovah shall be between them both' means enquiry made through truths from the Word regarding every single aspect of these things. This is clear from the meaning of 'an oath' as confirming through truths, dealt with in 2842, 3037, 3375, so that 'an oath of Jehovah' means doing so through truths from the Word, for the Word contains Jehovah's truths, that is, God's truths; and from the meaning of 'them both' as in every single aspect, for in the internal sense 'between both' does not mean between two but in every single aspect. 'Two' means things joined together to make a single whole, 1686, 3519, 5194, 8423, thus all that composes the whole, or every single aspect of it. This is what those in heaven perceive 'two' to be; and the reason why they do so is that when a discussion takes place among angels regarding two truths at variance with each other, a scene in which two spirits are arguing with each other presents itself on the level below. And since these spirits are the subordinates of a number of communities, every single aspect of one truth appears with one spirit, and every single aspect of the other truth with the other spirit. From this the angels perceive how the two are able to be linked together. I have been allowed to know from experience that this is what happens. So it is that when the words 'them both' are used in reference to truths they mean in every single aspect. This also is the reason why 'two' means something complete, 9103.
 The reason why it was permissible among the Israelite and Jewish nation to swear by Jehovah was that they were not internal, only external people, and when they engaged in the worship of God they did so on an external and not an internal level. The fact that they were like this, see 4281, 4293, 4429, 4433, 4680, 4844, 4847, 4865, 4903, 6304, 8588, 8788, 8806. When the confirmation of a truth comes down into the external man separated from the internal, it is effected by means of an oath; but not so when it comes down into the external by way of the internal. For in the internal man truth appears in its own light, but in the external without the internal truth appears in darkness. This explains why the celestial angels, who inhabit the inmost or third heaven, being in the highest degree of light do not even confirm truths by the use of reasons. Still less do they engage in argument and reasoning about truths; they simply say Yes or No, which they do by virtue of an ability received from the Lord to perceive and see them.
 This explains why the Lord has said the following regarding oaths,
You have heard that it was said, You shall not swear falsely, but shall perform to the Lord your oaths. But I say to you, You shall not swear at all, neither by heaven, for it is God's throne, nor by the earth, for it is His footstool, nor by Jerusalem, for it is the city of the great King. Nor shall you swear by your head, for you cannot make one hair white or black. But let your words be, Yes, yes; No, no; anything beyond this is from evil.a Matt 5:33-37.
These words imply that confirmation of God's truths should come from the Lord and not from man, which it does when people are internal and not external. For people who are external confirm truths by means of oaths, but those who are internal do so by means of reasons, while those who are even more internal do not confirm them at all but simply say It is so, or It isn't so. Those who are external are called natural people, those who are internal are called spiritual people, and those even more internal are called celestial people. The last of these - celestial people - have the ability, received from the Lord, to perceive intuitively whether something is true or not, see 2708, 2715, 2718, 3246, 4448, 7877. All this shows what was implied when the Lord said, You shall not swear at all, and also Let your words be Yes, yes; No, no. But why He also said that they were not to swear by heaven, by the earth, by Jerusalem, or by their head, and that any words beyond 'Yes, yes; No, no' are from evil, must be explained.
 Swearing by heaven means doing so by Divine Truth, thus by the Lord there. Heaven is heaven not by virtue of the angels regarded in themselves but by virtue of the Divine Truth emanating from the Lord, thus by virtue of the Lord Himself, within them; for the Divine within them is what enables them to be angels of heaven and be called angels of heaven. This explains why those in heaven are said to be 'in the Lord', why the Lord is the All in every single thing of heaven, and also why angels are God's truths, being recipients of God's truth emanating from the Lord.
Heaven is heaven and is called heaven by virtue of what is Divine and the Lord's there, see 552, 3038, 3700. Angels are God's truths, 4295, 4402, 7268, 7873, 8301. Something of the Lord is meant by an angel in the Word, 1925, 2821, 3039, 4085, 4295, 6280.
Since heaven is the Lord in respect of Divine Truth, it says 'you shall not swear by heaven, for it is God's throne'. 'God's throne' is Divine Truth which emanates from the Lord, 5313, 6397, 9039.
 Swearing by the earth however is doing so by the Church, thus by Divine Truth there. For just as heaven is the Lord by virtue of Divine Truth that emanates from Him, so too is the Church, the Church being the Lord's heaven or His kingdom on earth. For the meaning of 'earth' in the Word as the Church, see 662, 1066, 1262, 1733, 1850, 2117, 2118 (end), 2928, 3355, 4447, 4535, 5577, 8011, 8732. And since 'the earth' is the Church, the place where what is Divine and the Lord's below heaven exists, it says 'you shall not swear by the earth, for it is God's footstool'. 'Footstool' means God's truth below heaven, which is truth as it exists in the literal sense of the Word; for on this sense God's truth in heaven, which is the Word in the internal sense, rests and so to speak stands. Truth as it exists in the literal sense is meant by 'footstool' in David, in Ps 99:5; 132:7; in Isaiah 60:13; and in Jeremiah, in Lamentations 2:1.
 Swearing by Jerusalem however is doing so by teachings that present truth drawn from the Word. For in a broad sense 'Jerusalem' is the Church, 2117, 3654; but when the words 'the earth', meaning the Church, are used, followed by 'Jerusalem', 'Jerusalem' then means the Church's teachings, consequently teachings that present God's truth drawn from the Word. This is why it is called 'the city of the great [King, who is] God', for 'city' in the internal sense of the Word means teachings that present the truth, see 402, 2449, 2943, 3216, 4478, 4492, 4493.
 Swearing by his head however means a person's doing so by the truth which he himself believes to be the truth and makes part of his faith; for this as it resides with him constitutes 'his head', and it is also what is meant by 'the head' in Isaiah 15:2; 29:10; in Ezekiel 7:18; 13:18; 16:12; 29:18; in Matthew 6:17; and elsewhere. Therefore it also says, 'for you cannot make one hair white or black'. 'Hair' means truth belonging to the external or natural man, 3301, the kind that exists with those who believe the truth not because they perceive it to be the truth but because the teachings of the Church declare it to be so. And since they know the truth on no other grounds than this it says that they are not to swear by it because they cannot make a hair white or black. 'Making a hair white' means declaring on one's own authority that truth is truth, and 'making a hair black' declaring on one's own authority that falsity is falsity. For 'white' is said in reference to truth, 3301, 3993, 4007, 5319, and therefore 'black' in reference to falsity.
 From all this one may now see what is meant by the command not to swear at all, not by heaven, nor by the earth, nor by Jerusalem, nor by one's head, namely that a person should not use what is his own to confirm God's truth but what is the Lord's with him. Therefore it also says finally, Your words shall be Yes, yes; No, no; anything beyond this is from evil. Those who have the ability, which comes from the Lord, to perceive and see truth confirm it in this way alone, even as angels of the inmost or third heaven do, the ones who are called celestial angels, spoken about above. The reason why any words beyond 'Yes, yes; No, no' are from evil is that anything beyond them does not come from the Lord but from a person's proprium or self, thus from evil, since a person's proprium is nothing but evil, see 210, 215, 874-876, 987, 1023, 1044, 1047, 3812 (end), 4328, 5660, 8941, 8944. All this again shows in what way the Lord spoke, that is to say, in such a way that every single word contained an inner meaning, since He spoke from the Divine. Thus He spoke for the benefit of angels at the same time as for men; for angels perceive the Word according to its inner meaning.