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.

4283. 'He said, Let me go, for the dawn is coming up' means that the temptation came to an end when the joining together was at hand. This is clear from the meaning of 'letting me go' - that is to say, 'give up wrestling with me' - as the ending of the temptation (for 'wrestling' means temptation, see above in 4274; and the fact that it did come to an end is evident from what follows); and from the meaning of 'the dawn' as the joining of natural good, meant by 'Jacob', to the celestial-spiritual, that is, to the Divine good of truth, also dealt with above in 4275.

[2] The reason why the wrestling began before the dawn came up and why it finished after it came up, and why what happened when the sun had risen is mentioned after that, is that the times of day, like the seasons of the year, mean states, 487, 488, 493, 893, 2788, 3785. At present the state of conjunction effected by temptations is meant; for when the joining of the internal man to the external takes place it is 'dawn' to him, because at that time he enters a spiritual or a celestial state. At that time also light like that at dawn is seen by him, if his state is such that he is able to observe it. What is more, the understanding part of his mind receives light and becomes for him like the experience of waking up in the morning from sleep, when dawn first sheds her light and starts off the day.