A table-like structure, on which sacrifices and incense were offered, built of various materials, usually of stone, but sometimes of brass, etc. It is evident that sacrifices were offered long before the flood; but the first mention of an altar in Scripture is when Noah left the ark. Mention is made of altars reared by Abraham, Isaac, Jacob, and Moses. The latter was commanded to build an altar of earth, Exodus 20:24. If stone was employed, it must be rough and unhewn, probably lest the practice of sculpture should lead them to violate the second commandment. It was not to be furnished with steps, Deuteronomy 27:2-6.
The altars in the Jewish tabernacle, and in the temple at Jerusalem, were the following: 1. The altar of burnt offerings. 2. The altar of incense. 3. The table of showbread, for which see BREAD.
1. THE ALTAR OF BURNT-OFFERINGS was a kind of coffer of shittim- wood covered with brass plates, about seven feet six inches square, and four feet six inches in height. At the four corners were four horns, or elevations. It was portable, and had rings and staves for bearing in, Exodus 27:1-28:43. It was placed in the court before the tabernacle, towards the east. The furniture of the altar was of brass, and consisted of a pan, to receive the ashes that fell through the grating; shovels; basins, to contain the blood with which the altar was sprinkled; and forks, to turn and remove the pieces of flesh upon the coals. The fire was a perpetual one, kindled miraculously, and carefully cherished. Upon this altar the lamb of the daily morning and evening sacrifice was offered, and the other stated and voluntary blood-sacrifices and meat and drink-offerings. To this also certain fugitives were allowed to flee and find protection. The altar in Solomon’s temple was larger, being about thirty feet square and fifteen feet high, 2 Chronicles 4:1. It is said to have been covered with thick plates of brass and filled with stones, with an ascent on the east side. It is often called "the brazen altar."
2. THE ALTAR OF INCENSE was a small table of shittim-wood, covered with plates of gold; it was eighteen inches square, and three feet high, Exodus 30:1-38 37:25, etc. At the four corners were four horns, and all around its top was a little border or crown. On each side were two rings, into which staves might be inserted for the purpose of carrying it. It stood in the Holy place; not in the Holy of Holies, but before it, between the golden candlestick and the table of showbread, and the priests burned incense upon it every morning and evening. So Zacharias, Luke 1:9,11. See TEMPLE.
3. ALTAR AT ATHENS, inscribed "to the unknown God," Acts 17:23. It is certain. Both from Paul’s assertion and the testimony of Greek writers, that altars to an unknown or gods existed at Athens. But the attempt to ascertain definitely whom the Athenians worshipped under this appellation must ever remain fruitless for want of sufficient data. The inscription afforded to Paul a happy occasion of proclaiming the gospel; and those who embraced it found it indeed that the Being whom they had thus ignorantly worshipped was the one only living and true God.