The first altar mentioned in the Word was the one built by Noah after he came out of the ark, after being saved from the great flood. On that altar, he sacrificed clean animals to the Lord.

Mountains represent the Lord because of their height; we need to raise our thoughts above worldly things when "talking" with the Lord. An altar is a small artificial mountain. When it's used in worship, it can call to mind this raising of thought. The fire and smoke that rise from an altar are symbolically being sent to the Lord.

Most altars were made from unhewn stones. Stones represent truths. Unhewn stones - ones that have not been shaped by men - represent truths from the Word, truths that have not been adulterated.

The clean beasts to be sacrificed represent good things, charitable acts done because they are right. The clean birds represent thoughts about doctrine and actions, and about what is right. Presenting these things is an acknowledgment that we have them from the Lord, and a giving thanks to Him for them.

In the Israelitish Tabernacle, the altar of burnt offering represented the acknowledgment of good and the altar of incense that of truth. For this reason this larger altar, which was outside by the door, was made of brass which signifies natural good, while the altar of incense was made of gold, which signifies love to the Lord from whom comes truth.

5249. 'And came to Pharaoh' means a communication with the new natural. This is clear from the meaning of 'coming' in this instance as a communication through influx; and from the representation of 'Pharaoh' as the new natural, dealt with in 5079, 5080, 5244. What the words in this verse hold within them is evident from the explanations of them that have been given; for those words describe how Joseph was set free from the pit and came to Pharaoh. In the internal sense 'Joseph' represents the Lord so far as the celestial of the spiritual is concerned, while 'Pharaoh' represents the natural or external man. 'The pit' in which Joseph was confined represents a state of temptation endured by the Lord which involved the celestial of the spiritual, while his being called from the pit by Pharaoh means a state of release from temptations, and also a state of influx and communication after that with the new natural. From all this it is evident that the internal sense contains a description at this point of how the Lord made His Natural new and at length Divine.

[2] These are the matters that celestial angels contemplate when such historical details are read by man. To contemplate such matters is also their greatest delight, for they live in the Lord's Divine sphere and so they are as it were in the Lord. They know the deepest joy when they are thinking about the Lord and about the salvation of the human race, which took place because the Lord made the Human within Himself Divine. Also, to enable angels to go on experiencing that most heavenly joy and at the same time wisdom, a full description of that Divine process has therefore been given in the internal sense of the Word. This sense includes at the same time the process by which man is regenerated, for man's regeneration is an image of the Lord's glorification, 3138, 3212, 3296, 3490, 4402. Many will perhaps be wondering what angels talk about to one another and consequently what people after death who become angels talk about. Let those who so wonder know that angels talk about the kinds of matters that are contained in the internal sense of the Word, that is to say, about the Lord's glorification, His kingdom, the Church, the regeneration of man by means of the good of love and the truth of faith. But when they do so they use profound ideas which for the most part are beyond description.