24 An altar of earth thou shalt make unto me, and shalt sacrifice thereon thy burnt offerings, and thy peace offerings, thy sheep, and thine oxen: in all places where I record my name I will come unto thee, and I will bless thee.

25 And if thou wilt make me an altar of stone, thou shalt not build it of hewn stone: for if thou lift up thy tool upon it, thou hast polluted it.

26 Neither shalt thou go up by steps unto mine altar, that thy nakedness be not discovered thereon.

In the last post we discussed how the Israelites were not to create any graven image, even of the Lord Himself. Today we see that this forbidding of graven religious artifacts extended also to the altar upon which they would make their sacrifices. They were not to carve the stone into closely-fitting shapes, but instead would lay the rocks in a rough and natural pile.

God goes so far as to say that using a tool on the stone would pollute it. The altar was the most sacred place in the Jewish faith, and so it was to be a work of God alone. God crafted the rocks of the earth, and man was not supposed to try and improve on that. If they did, it would be an altar of men, not of the Lord.

Neither were they to craft stairs leading up to the altar, but approach it on level ground. The reason given is not because the stairs would be a constructed edifice, though, but because there might be a risk of the priestly skirt exposing a man as he ascended the stairs. For later altars the Lord would instruct the Israelites to elevate it up in the air, but by that point He also would have instructed the priests to wear breeches underneath their skirts.

This is a recurring pattern in the Biblical account. The Lord requires a holy practice of His people, but He modifies its requirement according to their capability at the time. Another example would be how the newly-freed Israelites, wandering back-and-forth through the wilderness, were told to construct a tabernacle that was portable and modest, whereas at the height of their power—under the reign of King Solomon—the temple would be a vast and permanent construction. In some things the Lord demands sudden, dramatic changes, but in other things He leads His people by degrees.