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.

1171. 'The sons of Raamah' similarly means those who had no internal worship but cognitions of faith, in the mere possession of which they made religion consist; and 'Sheba and Dedan' are nations with whom they existed and by these same nations cognitions themselves are meant in the internal sense. This is evident from the places in the Prophets given below, and from the following in David concerning Seba, Sheba, and Raamah,

The kings of Tarshish and of the islands will bring a gift, and the kings of Sheba and Seba will offer a present; and all kings will fall down before Him. Psalms 72:10-11.

This refers to the Lord, His kingdom, and the celestial Church. Anyone may see that here 'gift' and 'present' mean types of worship, though exactly which types of worship, and the nature of them, cannot be known unless it is known what 'Tarshish and the islands' and 'Sheba and Seba' are used to mean. The fact that 'Tarshish and the islands' is used to mean forms of external worship corresponding to internal has been shown already, from which it follows that 'Sheba and Seba' is used to mean forms of internal worship - 'Sheba' the celestial things of worship, and 'Seba' the spiritual.

[2] In Isaiah,

I gave Egypt as your expiation, Cush and Seba in place of you. Isaiah 43:3.

Here 'Cush and Seba' stands for the spiritual things of faith. In the same prophet,

The labour of Egypt, and the wares of Cush and of the Sabeans, men of stature, will come over to you. Isaiah 45:14.

'The labour of Egypt' stands for knowledge, 'the wares of Cush and the Sabeans' for cognitions of spiritual things which serve people who believe in the Lord.

[3] In the same prophet,

A drove of camels will cover you, dromedaries of Midian and Ephah; all those from Sheba will come. They will bring gold and frankincense and will proclaim the praises of Jehovah. The whole Rock of Arabia will be gathered to you. Isaiah 60:6-7.

Here 'Sheba' is used to mean celestial things and the spiritual things deriving from these, described as 'gold and frankincense', which, as now explained, are 'the praises of Jehovah', that is, internal worship.

[4] In Ezekiel,

The traders of Sheba and Raamah, they were your traders in the best of every spice, and in every precious stone, and they gave gold for your resources. Ezekiel 27:22-23.

This refers to Tyre. What 'Sheba and Raamah' means is clear from the commodities in which they are said to have traded - spices, precious stones, and gold. 'Spices' in the internal sense are charity, 'precious stones' are faith deriving from charity, and 'gold' is love to the Lord, all of which are the celestial things meant by 'Sheba'. Strictly, 'Sheba' means the cognitions of those things - and this is why they are here called 'merchandise' - with which those who become members of the Church are endowed, for without cognitions no one is able to become a member of the Church.

[5] Similar things were represented by the Queen of Sheba who came to Solomon and brought him spices, gold, and precious stones, 1 Kings 10:1-3, and also by the wise men from the east who came to Jesus at His birth, and who fell down and worshipped Him, and who opened their treasures, and offered Him gifts, gold, frankincense, and myrrh, Matthew 2:1, 11. These gifts meant celestial, spiritual, and natural good. In Jeremiah,

To what purpose does frankincense come to Me from Sheba, and best sweet cane from a distant land? Your burnt offerings are not acceptable. Jeremiah 6:20.

Here also it is evident that 'Sheba' stands for cognitions and adoration, meant by 'frankincense and sweet cane', though here they are those things devoid of charity, which are not pleasing.