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.

1944. That 'behold, you are with child' means the life of the rational man is clear from what has been stated above about the conception of that man and from what follows regarding Ishmael, to the effect that the Lord's first rational is represented by him. With regard to the rational man in general it should be recognized that the rational is said to receive life, to be in the womb, and to be born, as soon as a person starts to think that within him evil and falsity are present which contradict and show opposition to truth and good, increasingly so when he wishes to remove and subdue such evil and falsity. Unless he is able to see and appreciate this, he does not have any rational, however much he imagines that he does. For the rational is the means which unites the internal man to the external, thereby perceiving from the Lord what is taking place in the external man. The rational also brings the external into a position of obedience - or rather raises it up from the bodily and worldly interests in which it immerses itself - and causes the person to be truly human, who as a result looks up to heaven where he belongs by birth, and not, as animals do, solely down to the earth, where he resides merely temporarily, and certainly not down to hell. These are the functions of the rational, and therefore unless a person is such that he is able to think in this manner, he cannot be said to have a rational. Whether the rational exists at all is recognizable from the life belonging to the use or function it performs.

[2] His reasoning against good and truth - which good and truth he denies in his heart, yet has heard of and therefore knows of - does not mean that he has a rational. Many are able to reason in the same way who without any compunction rush into every kind of wicked action, and who differ from others only in this respect, that those people who suppose they have a rational, but in fact do not, display a certain correctness in the things they say and a presence of honourableness in the things they do, and are held to these habits by means of external restraints, such as fear of the law, and of the loss of possessions, position, reputation, or life. If these restraints, which are external, were taken away, some of these people would behave even more insanely than those who have no compunction at all. Nobody therefore can be said to have a rational merely on account of an ability to reason. Indeed those who do not have a rational usually speak from sensory experience and factual knowledge with far greater skill than those who do have it.

[3] This is absolutely clear from evil spirits in the next life who, though they were considered to be the most rational of people during their lifetime, are nevertheless more insane than those who are obviously so in the world, when the external restraints which had been responsible for their correctness in the things they said and for the presence of honourableness in the things they did are removed, as such restraints usually are with all in the next life. Indeed they plunge without shame, fear, or horror into everything that is wicked. Not so when external restraints are removed in the case of people who were rational when they lived in the world; they are saner men still because they have internal restraints, which are the restraints of conscience, by which the Lord has kept their thoughts bound to the laws of truth and good, which constituted their rational concepts.