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.

1050. 'And with every living soul in all flesh' means the entire human race. This is clear from the meaning of 'living soul in all flesh'. Every individual is called 'a living soul' from that which is living within him. No one can possibly live, let alone as a human being, if he does not have something living within him, that is, if he does not have some measure of 'innocence, charity, and mercy, or from these something of a similar or comparable nature. This measure of innocence, charity, and mercy a person receives from the Lord when he is an infant and during childhood, as becomes clear from the state of infants and also from that of childhood. What a person receives at that time is preserved within him, and the things that are preserved are in the Word called 'remnants', which are the Lord's alone with a person. These remnants that are being preserved are what make it possible for someone when he becomes adult to be a human being. Regarding these remnants, see what appears in 468, 530, 560-563, 576.

[2] That the states of innocence, charity, and mercy that have been his in infancy and in childhood years enable a person to be human is quite clear from the fact that man is not born as animals are, ready to perform any of life's activities, but has to learn how to do every single one. The things he learns to do then become through the performance of them habitual and so to speak natural to him. Man is not even able to walk, or to talk, until he learns how to do so; and the same applies to everything else. Through usage these activities become so to speak natural to him. The situation is the same with regard to the states of innocence, charity, and mercy with which likewise he is endowed from infancy. But for these states man would be far inferior to any animal. These states however are not states that man acquires by learning but ones which he receives as a free gift from the Lord, and which the Lord preserves within him. These, together with truths of faith, are what are also called remnants and are the Lord's alone. To the extent that a person in adult life destroys these states, he becomes a dead man. When a person is being regenerated these states are the principal agents of regeneration, and he is brought into these states, for, as stated already, the Lord works by means of remnants.

[3] These remnants present with everybody are what are here called 'the living soul in all flesh'. That 'all flesh' means everybody and so the entire human race becomes clear from the meaning of 'flesh' in many places in the Word - see what has been shown in 574 - as in Matthew,

Unless those days were shortened, no flesh would be saved. Matthew 24:22; Mark 13:20.

In John,

Jesus said, Father, glorify Your Son, as You have given Him power over all flesh. John 17:1-2.

In Isaiah,

The glory of Jehovah will be revealed, and all flesh will see it. Isaiah 40:5.

In the same prophet,

All flesh will know that I am Jehovah your Saviour. Isaiah 49:26.