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.

289. 'Wife' is used to mean the Church, in the universal sense the Lord's kingdom in heaven and on earth. This too has been shown already, while the fact that 'mother' as well has the same meaning follows from this. In the Word the Church is commonly called 'mother', as in Isaiah,

Where is your mother's bill of divorce? Isaiah 50:1.

In Jeremiah,

Your, mother has been utterly shamed, she who bore you is covered with shame. Jeremiah 50:12.

In Ezekiel,

[You are] your mother's daughter who loathes her husband and her sons. Your mother is a Hittite and your father an Amorite. Ezekiel 16:45.

Here 'husband' (vir) stands for the Lord and everything celestial, 'sons for truths of faith, 'Hittite' for falsity, and 'Amorite' for evil. In the same prophet,

Your mother was like a vine in your likeness, planted beside the waters, fruitful, full of branches by reason of many waters. Ezekiel 19:10.

Here 'mother' stands for the Ancient Church. The Most Ancient Church is pre-eminently called a 'mother' because it was the first Church, and the only one to be celestial. For that reason it was the Lord's beloved more than any other.