'A plain' signifies the extremes of the Word regarding doctrine, and also the extremes of the church, or people in extremes of truths and goods. It also signifies good and truth in the natural self, because 'the people who dwell in plains,' or 'beneath mountains and hills' are in the extreme heaven. In Genesis 19:17, this signifies all doctrinal matters.

In Genesis 11:2, this signifies that their worship became more impure and profane. (Arcana Coelestia 1292)

In Jeremiah 21:13, this signifies the faith in which is no charity. (Arcana Coelestia 4715) Plain and valley signifies the ultimates of the Word. (Apocalypse Explained 411) Plain signifies good and truth in the natural man, because people in the First Heaven dwell in plain or valley. (Apocalypse Explained 449)

(Reference: Apocalypse Explained 400)

4715. 'And he sent him out of the Valley of Hebron' means going forth from the Divine Natural and Sensory degrees. This is clear from the meaning of 'being sent' as going forth and teaching, dealt with above in 4710; from the meaning of 'a valley' as things that are low, dealt with in 1723, 3417; and from the meaning of 'Hebron' as the Lord's Church as regards good, dealt with in 2909. The words used at this point accordingly mean that it was to teach the lower things of the Church, for the reason that people would not grasp the higher ones. Indeed one who teaches faith and not charity cannot possibly discern the higher and more internal things of the Church since he does not possess the wherewithal that leads him to see and lays down for him whether a particular idea is part of faith or is the truth. But if he teaches charity he is in that case in possession of good. Good lays down the truth for him and leads him, for all truth stems from good and has to do with good; or what amounts to the same, every aspect of faith stems from charity and has to do with charity. The fact that everything taught by doctrine has regard to life anybody can recognize from natural enlightenment alone.

[2] The meaning 'going forth from the Divine Natural and Sensory degrees' carried by the words used here is their higher meaning. For the expression 'lower things of the Church' is used to describe those which have their origin in the Lord's Divine Natural and Sensory degrees. Not that within the Lord these things are lower ones - for within the Lord and within His Divine Human everything is Infinite, indeed He is Jehovah as regards both Essences, 2156, 2329, 2921, 3023. Those things are lower because of what the situation is with man. People who are sensory-minded rely on ideas as grasped by the senses to think of things which exist within the Lord and which go forth from the Lord, and those who are natural-minded rely on natural ideas. The nature of the recipients is the reason for the way any matter is stated. People however who are heavenly-minded and are as a consequence truly rational do perceive interior things. These are the ones of whom it is said that they teach from the Lord's Divine Rational. This, as has been stated, is the higher meaning which these words carry.

[3] The meaning of 'a valley' as the lower things of the Church may be seen from other places in the Word, as in Isaiah,

The prophecy of the valley of vision. What is this, that you have gone up, every one onto the housetops? The Lord Jehovih Zebaoth has a day of tumult and of trampling and of confusion in the valley of vision. Isaiah 22:1, 5.

'The valley of vision' stands for false notions about spiritual things - notions formed from sensory impressions, and so from lower things. In the same prophet,

The choicest of your valleys were filled with chariots, and the horsemen positioned themselves at the gate. Isaiah 22:7.

'The choicest of the valleys' stands for goods and truths within the natural or external man. In the same prophet,

The voice of one crying in the wilderness, Prepare the way of Jehovah; make plain in the lonely place a highway for our God; every valley will be lifted up. Isaiah 40:3-4.

'Valley' stands for things that are lowly.

[4] In Jeremiah,

How will you say, I have not been defiled, I have not gone after the baalim. Look at your way in the valley; acknowledge what you have done. Jeremiah 2:23.

'The valley' stands for factual knowledge and sensory impressions, which are lower things, by means of which they would pervert truths. In the same prophet,

I am against you, O inhabitant of the valley, O rock of the plain, said Jehovah, you who say, Who will come down against us? Jeremiah 21:13.

'Inhabitant of the valley' and 'rock of the plain' stand for faith which has no charity in it. In the same prophet,

He who lays waste will come upon every city, and no city will escape; but the valley will perish, and the plain will be destroyed. Jeremiah 48:8.

Here the meaning is similar. In the same prophet,

You will not boast of valleys; your valley has flowed away, O perverse daughter. Jeremiah 49:4.

'Valley' stands for the external things within worship which are also the lowest.

[5] In Ezekiel,

I will give to Gog a place for burial in Israel, the valley of those that pass over. There they will bury Gog and all his multitude, from which they will call it the valley of the multitude of Gog. Ezekiel 39:11, 15.

'Gog' stands for those whose worship is external devoid of internal, 1151, which is why the expressions 'his grave', 'the valley of those that pass over', and 'the valley of his multitude' are used. In David,

Even when I walk in the valley of the shadow I will fear no evil. Psalms 23:4.

'The valley of the shadow' stands for lower things which, compared with others, are in shadow.

[6] Because valleys lay between mountains and hills and beneath them, 'valleys' therefore means the lower or more external things of the Church; for 'hills' and 'mountains' mean the higher or more internal things of it, 'hills' things of charity and 'mountains' those of love to the Lord, 795, 1430, 2722, 4210. And because 'the land of Canaan' means the Lord's kingdom and His Church, that Church is therefore called,

A land of mountain's and valleys, on the arrival of the rain of heaven it drinks water. Deuteronomy 11:11.

The reason Joseph is said at this point of have been sent out of the Valley of Hebron is that he was sent to those who taught about faith, 4705.

Those who are governed by faith, not by charity, adhere to lower things, for with them faith exists merely in the memory and consequently on the lips, not in the heart and consequently in action.