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.

1989. That 'Abram' means the Lord in that state and at that age is clear from what has been stated already about Abram. In the internal sense Abram represents the Lord, for when mentioned in the Word no other Abram is meant in heaven. People who have been born inside the Church and have heard of him from the Word do indeed know of Abram when they enter the next life, but because he is no different from any other human being and cannot be of any help to them, they are no longer interested in him. Furthermore they are informed that in the Word 'Abram' has been used to mean no one other than the Lord. Indeed angels, who possess heavenly ideas but form no image of any man with them, know nothing at all about Abram. Consequently when the Word is read by man and Abram is mentioned they perceive no one other than the Lord. And in the statement made here they perceive the Lord passing through that state and that age, for here Jehovah is talking to Abram, that is, to the Lord.