The same book of the Law was preserved and handed down to posterity by the Samaritans, and therefore was received by the ten Tribes before their captivity. For when the ten Tribes (2 Kings 17:27, 28, 32, 33) were captivated, a Priest of the captivity was sent back to Bethel, by order of the King of Assyria, to instruct the new inhabitants of Samaria, in the manner of the God of the land; and the Samaritans had the Pentateuch from this Priest, as containing the law or manner of the God of the land, which he was to teach them. For they persevered (2 Kings 17:34, 41) in the religion which he taught them, joining with it the worship of their own Gods; and by persevering in what they had been taught, they preserved this book of their Law in the original character of the Hebrews, while the two Tribes, after their return from Babylon, changed the character to that of the Chaldees, which they had learned at Babylon.
And since the Pentateuch was received as the book of the Law, both by the two Tribes and by the ten Tribes, it follows that they received it before they became divided into two Kingdoms. For after the division, they received not laws from one another, but continued at variance. Judah could not reclaim Israel from the sin of Jeroboam, and Israel could not bring Judah to it. The Pentateuch therefore was the book of the Law in the days of David and Solomon. The affairs of the Tabernacle and Temple were ordered by David and Solomon, according to the Law of this book; and David in the 78th Psalm, admonishing the people to give ear to the Law of God, means the Law of this book. For in describing how their forefathers kept it not, he quotes many historical things out of the books of Exodus and Numbers.