Altar
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.
Isaiah 54
1
"Sing, barren, you who didn't bear; break forth into singing, and cry aloud, you who did not travail with child: for more are the children of the desolate than the children of the married wife," says Yahweh.
2
"Enlarge the place of your tent, and let them stretch forth the curtains of your habitations; don't spare: lengthen your cords, and strengthen your stakes.
3
For you shall spread out on the right hand and on the left; and your seed shall possess the nations, and make the desolate cities to be inhabited.
4
"Don't be afraid; for you shall not be ashamed: neither be confounded; for you shall not be disappointed: for you shall forget the shame of your youth; and the reproach of your widowhood you shall remember no more.
5
For your Maker is your husband; Yahweh of Armies is his name: and the Holy One of Israel is your Redeemer; the God of the whole earth shall he be called.
6
For Yahweh has called you as a wife forsaken and grieved in spirit, even a wife of youth, when she is cast off," says your God.
7
"For a small moment have I forsaken you; but with great mercies will I gather you.
8
In overflowing wrath I hid my face from you for a moment; but with everlasting loving kindness will I have mercy on you," says Yahweh your Redeemer.
9
"For this is like the waters of Noah to me; for as I have sworn that the waters of Noah shall no more go over the earth, so have I sworn that I will not be angry with you, nor rebuke you.
10
For the mountains may depart, and the hills be removed; but my loving kindness shall not depart from you, neither shall my covenant of peace be removed," says Yahweh who has mercy on you.
11
"You afflicted, tossed with storms, and not comforted, behold, I will set your stones in beautiful colors, and lay your foundations with sapphires.
12
I will make your pinnacles of rubies, and your gates of sparkling jewels, and all your walls of precious stones.
13
All your children shall be taught of Yahweh; and great shall be the peace of your children.
14
In righteousness you shall be established: you shall be far from oppression, for you shall not be afraid; and from terror, for it shall not come near you.
15
Behold, they may gather together, but not by me: whoever shall gather together against you shall fall because of you.
16
"Behold, I have created the smith who blows the fire of coals, and brings forth a weapon for his work; and I have created the waster to destroy.
17
No weapon that is formed against you will prevail; and you will condemn every tongue that rises against you in judgment. This is the heritage of the servants of Yahweh, and their righteousness which is of me," says Yahweh.
