Ver. 2. On the day when ye shall pass over Jordan— Day here, as well as in the former verse, signifies time. See Joshua 8:30. It is not said how many great stones they were to set up; neither can we determine their number, unless we knew exactly how much of the law was to be written, whether the whole book of Deuteronomy, or only the ten commandments, or the curses and the blessings. They are ordered to plaister over these stones with plaister. This plaister has been generally understood, as meant to be laid over the stones, to give them smooth surfaces, that so the law might be inscribed upon that plaister. But the very next words shew, that the words were not to be inscribed upon it, i.e. the plaister; but upon them, i.e. the stones. Besides, if duration was not intended, the original tables were present, and might have been used for a single recital of the commandments on this extraordinary occasion: and if duration was intended, covering the surfaces of the stones with plaister, notwithstanding what has been said of the tenacity of the ancient plaister, seems a method very unlikely to perpetuate the inscription; especially as the words are supposed to be inscribed as soon as the plaister was laid on. The learned Houbigant thinks, that the words do not mean plaister for the surfaces, but cement for the sides of these stones, by which they were to be joined firmly together:—caementum, quo lapides monumenti, unus ad unum, firme cohaererent. But, perhaps, the truth of the case is this: the letters on these stones were not to be sunk or hollowed out, but raised in relievo, and the stone cut from around the letters. The plaister would then be of excellent use to fill up the interstices of the letters: and if the plaister was white between the letters of black marble, the words would appear according to the command, ver. 8 very plainly, or, as in Coverdale's Version of 1535, manifestly and well. This hypothesis of the letters being raised may be strengthened, by observing, that the Arabic inscriptions, perhaps all that are now extant, are in relievo. The two Arabick marbles, preserved in the University of Oxford, are proofs of this method of engraving; which, therefore, might obtain formerly among the other oriental nations. Selden, in his account of the Oxford marbles, mentions four, numbered 191, 192, 193, 194, which have on them Hebrew characters, and were anciently parts of some sepulchral monuments of the Jews. But not knowing where these fragments are, I cannot say whether the letters upon them are in relievo, or the contrary. See Kennicott's Dissertation, 2: p. 77.

Ver. 3. All the words of this law— But what law? it may be asked. They must have been immense stones to have contained the whole book of Deuteronomy, much more the whole Pentateuch: either therefore the ten commandments, or the blessings and curses, must be meant.
1. Mr. Locke says, all the words, &c. means the decalogue; and Dr. Kennicott also is for the ten commandments, that divine system of the moral law, which, he says, may be well called the law, by way of eminence. In this sense the word is used Acts 7:53. At our entrance upon this consideration, the propriety of engraving the ten commandments on this occasion strikes us at once; for, Had not the Israelites been brought out of Egypt with a mighty hand, to possess the land of Canaan, there to live as the servants and subjects of the one true God? Was there not a covenant expressly made with them for this purpose on their entering into the wilderness? Did not the ten commandments, delivered by God, and the promise of obedience made by the people, constitute the principal part of that solemn covenant? And therefore, upon their taking possession of the land thus promised, what so proper to engrave on stones, and fix up near the centre of that country for public inspection, as those ten commandments, which make the principal part of that law, of that divine charter, which was to secure that country to them, and to their posterity? See the note on ver. 26. The two tables, containing these commandments, were then in the ark; and as the ark was, doubtless, near Moses, while he was thus solemnly addressing his brethren, we may consider him as pointing to that very law, when he said all the words of this law. But further, the covenant is expressly asserted to be the ten commandments, chap. Deu 4:13 and Exo 34:28 and if we allow the authority of the Samaritan text and version, we shall find in the addition of four verses between verses 10 and 11 of Exodus 20 that it expressly asserts, that the ten commandments were the law which was to be written upon the stones on this occasion. See Kennicott's 2nd Dissertation.
2. Josephus, however, understands the curses only at the end of this chapter to be meant, which curses, as will appear from the note on ver. 15 have a manifest reference to the ten commandments. Jos 8:34 appears, I think, decisive for the blessings and curses: for it is there said, speaking of Joshua's completing this injunction, that he read all the words of the law, the blessings and curses; where blessings and curses seem evidently in apposition with the words of the law. Be this as it may, it is certain, that before the invention of paper, the ancients, especially the Phoenicians and Egyptians, were accustomed to write upon stones those things whereof they were desirous to preserve the memory; various proofs of which may be found in Bishop Huet's Demonstr. Evang. prop. iv. c. 2.

Ver. 5. An altar of stones— It does not seem probable, that the altar was built of the very same stones on which the law was engraven; for this evident reason, that the altar was to be built of stones, rough, unhewn, untouched by any tool; whereas some hard tool or instrument of metal was necessary to engrave the commandments: and as they could not have been engraved, so neither could they have been read easily, unless the surfaces of the stones were previously smoothed by art and labour. These stones are limited to two, according to Dr. Kennicott; because two large stones would be sufficient, and because it was most obvious for the Israelites to engrave the commandments upon two; in imitation of the two tables on which they had received them from God himself. It also appears clear, that only two were meant; the Hebrew word being frequently used in the plural, or, as some call it, the dual number, without the numeral for two being expressed at all. Thus it is used, Gen 27:36 and thus abanim gedoloth, the very words used in the 1st verse of this chapter, are in the Latin versions of the Samaritan text, Exo 20:18 translated TWO great stones. Kennicott. Diss. 2: See Houbigant on this verse.
See commentary on Deu 27:4

Ver. 7. Thou shalt offer peace-offerings— As these offerings concerned the whole people, and all were to eat of them, and rejoice before the Lord: the opinion we have advanced of the altar's being placed in the midst of the plain gains great confirmation from hence; it being extremely improbable that they should all ascend the mount of cursing, or any other mount for that purpose.
REFLECTIONS.—The law being delivered, care is here taken to have the record preserved and attended to; for which purpose, 1. Moses, with the priests and princes of the people, that their numbers and dignity might give weight to the admonition, solemnly charges the people to be obedient. They were now in a distinguished manner declared to be the people of God, and therefore must approve themselves as became such a relation. Note; (1.) All, who have weight and influence over others, should join in promoting the work of religion among them. (2.) The honour and blessing of God's service is a strong obligation to serve him. (3.) When ministers and magistrates show themselves zealous in their station for God, it is much to be hoped that the people will hear and follow such good examples. 2. That none may plead ignorance, a copy of the law is ordered to be written on large stones plaistered over. Note; The word of God is so plain, that wilful ignorance of it is wilful sin. The altar must be built of stones unhewn and plain; for God's service requires no ornaments: he demands not the glided altar, but the holy heart. Burnt-offerings and peace-offerings were sacrificed to intimate how necessary it was to have the remedy of atoning blood near to save from the condemnation of a holy law; and they are commanded to eat and rejoice before the Lord: for they who, through the sacrifice of Jesus, are reconciled to God, delivered from the curse of the law, and admitted into a covenant of grace, have need to rejoice in the Lord, and glory in the God of their salvation. All these institutions are typical of our divine Redeemer. On him are our curses laid: he is at once our altar and sacrifice; and whosoever eats his flesh, and drinks his blood, cannot but rejoice before the Lord with joy unspeakable, and full of glory.

Ver. 12. Upon mount Gerizzim— By mount Gerizzim. To bless the people, that is, by saying Amen when they heard the blessings pronounced by the priests. See ver. 14, 15. The priests seem clearly to have stood round about the ark, placed near the altar in the valley between the two mountains; and, in pronouncing the benedictions, turned towards mount Gerizzim, where stood six of the tribes; and, in pronouncing the curses, towards mount Ebal, where stood the other six; as will appear more plainly from the following scheme of Dr. Parry's:
West
ARK
Priests. Priests. the the Levites. Levites.
South Simeon. Reuben. North
GERIZIM Levi. Gad. Judah. Asher Issachar. Zebulun.
Joseph. Dan. Benjamin. Naphtali. Strangers. Strangers. East EBAL

Ver. 15. Cursed be the man that maketh, &c.— The people being to bless, as well as to curse, the Mischna seems very justly to explain it thus: that first the priests, turning their faces towards mount Gerizzim, proclaimed aloud, Blessed be the man that maketh not any graven image; upon which the people standing by that mountain answered, Amen: then turning towards mount Ebal, they said, Cursed be the man that maketh, &c. to which they who stood by that mountain answered, Amen likewise: and so it is to be understood of all the rest. We may just observe, that, as be is not in the original, it might be as well rendered, cursed is the man; that is, he thus renders himself obnoxious to the divine malediction. If we examine the twelve curses, says Dr. Kennicott, they will appear to contain a strong enforcement of the ten commandments; and it is highly probable, that they were here proclaimed principally to secure obedience to them. The first curse included in this verse seems meant to answer to the four commandments of the first table, which enjoin the worship of the true God, and forbid idolatry; that in ver. 16 enforces the fifth commandment; those in ver. 18. 24 and 25 the sixth commandment; those in ver. 20, 21, 22, 23 enforce the seventh commandment, and guard the Israelites from the several species of obscenity in vogue among the Egyptians; ver. 17 establishes the eighth; ver. 19 relates to the ninth; and ver. 26 being a guard to all the precepts of God in general, is, in some measure, coincident with the tenth commandment: for that likewise is a guard to the preceding commandments, forbidding even to meditate injustice, or to entertain such desires as it would be criminal to indulge to the prejudice of our neighbour. Dissert. 2: p. 85. For explications of these several curses, we refer to the passages in the Margins of our Bibles. If it be asked, why a curse is denounced against the crimes here mentioned, where others no less atrocious are omitted,—one reason may be drawn from the preceding part of this note; and another may be, that these were the crimes most frequent among the Canaanites and their neighbours. The word amen, or so be it, has sometimes the force of an oath: sometimes it only declares consent and approbation; and sometimes it is used for confirmation. It is used in the first sense, Num 5:22 in the second, in this place, and in the third, Jeremiah 28:6. The secret place, mentioned in this verse, implies, that if a man was only a private worshipper of images, and did it ever so closely, yet was he subject to the malediction of that GOD to whom the secrets of all hearts are open. Public idolatry was punished with death.

Ver. 26. Cursed be he that confirmeth not all the words of this law— The original word, here rendered confirmeth, is very properly translated performeth, 1 Samuel 15:11. The performing of what God commands being a kind of establishment of the law, as disobedience is a subversion, and, as far as lies in the offender's power, an abolition of it; therefore the apostle exactly translates these words, Galatians 3:10. Cursed is every one that continueth not in all things which are written in the book of the law, to do them.
REFLECTIONS.—Observe, 1. The appointment of the tribes for their several posts is expressly appointed by God. The six more honourable tribes are appointed to bless: they are all the children of the free woman, and Levi is reckoned among them; for they who preach the blessing or curse to others need first apply them to their own hearts. 2. They are called to join in their Amen on the rehearsal of the curses as well as blessings. In the latter case, they expressed their desire after them; in the former, their confession of faith in the certainty of the threatened curse; their approbation of the sentence, as just; and an awful imprecation upon their souls, if they transgressed. Thus, out of their own mouths would they be condemned. Note; (1.) The curses of God against sin are awful realities. (2.) Ministers must urge the terrors of the Lord to persuade, as well as the love of Christ to constrain; and all little enough to influence the hard heart of man. (3.) In the day of God every sinner will be struck speechless, and left without excuse.