I. Classification of Hebrew Altars. – Before considering the Biblical texts attention must be drawn to the fact that these texts know of at least two kinds of altars which were so different in appearance that no contemporary could possibly confuse them. The first was an altar consisting of earth or unhewn stones. It had no fixed shape, but varied with the materials. It might consist of a rock (Judg 13:19) or a single large stone (1 Sam 14:33-35) or again a number of stones (1 Kings 18:31 f). It could have no horns, nor it would be impossible to give the stone horns without hewing it, nor would a heap of earth lend itself to the formation of horns. It could have no regular pattern for the same reason. On the other hand we meet with a group of passages that refer to altars of quite a different type. We read of horns, of fixed measurements, of a particular pattern, of bronze as the material. To bring home the difference more rapidly illustrations of the two types are given side by side. The first figure represents a cairn altar such as was in use in some other ancient religions. The second is a conjectural restoration of Hebrew altars of burnt offering and incense of the second kind.
Canaanite altars were constructed of earth, stone, or metal. Stone altars have been preserved in Israel. Their form ranges from unworked, detached rocks to carefully cut natural stone. Altars of earth are mentioned in the ancient records, but none have been preserved, with the possible exception of an Israelite altar at Arad. These were the simplest altars, probably built by the common people. ALTAR’S of earth were not eternal.