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.

9404. 'And seventy of the elders of Israel' means all who are governed by good which results from truths. This is clear from the meaning of 'seventy' as that which is complete, thus all things or all people, dealt with in 6508; and from the meaning of 'the elders of Israel' as those who are governed by good which results from truths and guided by truths which flow from good. For 'elders' in the Word means those with wisdom, 6524, thus those who lead a good life as a result of teachings declaring what is true; and 'Israel' means those who belong to the spiritual Church, 6426, 6637, 6862, 6868, 7035, 7062, 7198, 7201, 7215, 7223, 8805, 9340, thus those who are guided by truths that lead to good and governed by good from which truths flow, 7957, 8234. From all this it is evident that 'seventy elders of Israel' means those who are governed by good which results from truths, and that in the sense detached from persons that good itself is meant. The same is meant in the internal sense by 'the Lord's seventy disciples', Luke 10:1, 17. The children of Israel were divided into twelve tribes, which had twelve princes or governors set in authority over them, and also seventy elders. 'The twelve tribes' meant all the truths and forms of good the Church possesses in their entirety, 3858, 3926, 3939, 4060, 6335, 6337, 6397, 6640, 7836, 7891, 7996, 7997; but 'the twelve princes' meant all the primary truths, 5044, and 'the seventy elders' all the forms of good resulting from truths.

[2] When the expression 'good which results from truths' is used the spiritual Church is meant; for this Church is governed by good resulting from truths. Anyone unacquainted with the arcana of the Church and of heaven may think that, since good cannot be implanted except through truths, all the good in the Church exists as a result of truths, indeed that a person cannot know what good is except through truths. However, the good which arises through truths is the spiritual Church's good, which regarded in itself is truth but is called good when it becomes part of will and action, and consequently of life. But good that does not arise through truths but through forms of the good of mutual love is the celestial Church's good, which regarded in itself is not truth but good since it is the good of love to the Lord. The Jewish Church represented this second kind of good, whereas the Israelite Church represented the first; and this accounts for their division into two kingdoms. For what the essential difference is between those two Churches and consequently the two kinds of good, see what has been shown already in 2048, 2227, 2669, 2708 (end), 2715, 2718, 2935, 2937, 2954, 3166, 3235, 3236, 3240, 3246, 3374, 3833, 3887, 3969, 4138, 4286, 4493, 4585, 4938, 5113, 5150, 5922, 6289, 6296, 6366, 6427, 6435, 6500, 6647, 6648, 7091, 7233, 7877, 7977, 7992, 8042, 8152, 8234, 8521. From what has been introduced in these paragraphs it becomes clear that the Lord's heaven is divided into a spiritual heaven and a celestial heaven, and that the celestial heaven is the inmost or third heaven, while the spiritual heaven is the middle or second.