5 And there shalt thou build an altar unto Jehovah thy God, an altar of stones: thou shalt lift up no iron [tool] upon them. 6 Thou shalt build the altar of Jehovah thy God of unhewn stones; and thou shalt offer burnt-offerings thereon unto Jehovah thy God: 7 and thou shalt sacrifice peace-offerings, and shalt eat there; and thou shalt rejoice before Jehovah thy God. 8 And thou shalt write upon the stones all the words of this law very plainly.
Matthew Henry's Commentary on Deuteronomy 27:5-8
Commentary on Deuteronomy 27:1-10
(Read Deuteronomy 27:1-10)
As soon as they were come into Canaan, they must set up a monument, on which they must write the words of this law. They must set up an altar. The word and prayer must go together. Though they might not, of their own heads, set up any altar besides that at the tabernacle; yet, by the appointment of God, they might, upon special occasion. This altar must be made of unhewn stones, such as they found upon the field. Christ, our Altar, is a stone cut out of the mountain without hands, refused by the builders, as having no form or comeliness, but accepted of God the Father, and made the Head of the corner. In the Old Testament the words of the law are written, with the curse annexed; which would overcome us with horror, if we had not, in the New Testament, an altar erected close by, which gives consolation. Blessed be God, the printed copies of the Scriptures among us, do away the necessity of such methods as were presented to Israel. The end of the gospel ministry is, and the end of preachers ought to be, to make the word of God as plain as possible. Yet, unless the Spirit of God prosper such labours with Divine power, we shall not, even by these means, be made wise unto salvation: for this blessing we should therefore daily and earnestly pray.