He shall write; either with his own hand, as the Jews say; or, at least, by his command and procurement. Out of that which is before the priests the Levites, i.e. out of the original, which was carefully kept by the priests in the sanctuary, Deuteronomy 31:26 2 Kings 22:8, partly that it might be a true and perfect copy, and partly that it might have the greater authority and influence upon him, coming to him as from the hand and presence of God.
Related Commentaries of Deuteronomy 17:18
Deuteronomy 17:18
18 And it shall be, when he sitteth upon the throne of his kingdom, that he shall write him a copy of this law in a book out of that which is before the priests the Levites: