When he sits on the throne of his kingdom: this seems to refer to the day the man God has chosen is installed as king. Revised English Bible has “When he has ascended the throne of his kingdom”; or we may translate more generally, “when he begins to rule [or, reign],” or even “When he becomes king” (Good News Translation, Contemporary English Version). In cultures where chiefs rule, it may be necessary to talk about “sitting on his chair [or, stool].”

He shall write for himself in a book a copy of this law: the meaning of this part of the sentence is not completely clear. Revised Standard Version takes it to mean that the king himself is to make a copy of this law; but the text may mean “he is to have a copy made for him.” So New Revised Standard Version has “he shall have a copy of this law written for him” (also New Jewish Publication Society’s Tanakh, Good News Translation, Bible en français courant, Nova Tradução na Linguagem de Hoje, BÍBLIA para todos Edição Comum).

A book: here, more precisely, a scroll. If neither of these terms is available in a local language, the more general “he is to have a copy of this law made for him” may be used, without indicating the precise form the copy is to take.

There is much difference of opinion over the precise meaning of this law. The Hebrew noun is torah, which can mean:
(1) the complete Torah; this is most unlikely, but Good News Translation “the book of God’s laws and teachings” can be taken to mean this;
(2) the book of Deuteronomy, as we know it (see the use of this law in 1.5); this is the interpretation favored by most;
(3) a section of the book of Deuteronomy, especially chapters 12–26; while possible, this would be very difficult to indicate in translation.

Probably the best translation is to say “this book of the law,” without saying exactly what “this book” means; most readers will probably assume it means the book of Deuteronomy. However, if “book” is difficult to translate, we may simply say “a copy of these [or, God’s] laws.”

It is from the Septuagint translation of this verse that the book Deuteronomy gets its name. The Hebrew is “a copy of this law” (also Josh 8.32); the Septuagint translates “this second record of the law” (a similar translation in Josh 8.32).

From that which is in charge of the Levitical priests: the meaning of the Hebrew text here is disputed.
(1) Many take it as do Revised Standard Version and Good News Translation (and New International Version, Bible en français courant, Nova Tradução na Linguagem de Hoje, BÍBLIA para todos Edição Comum, Biblia Dios Habla Hoy), that the copy is to be made from the original, which is kept by the Levitical priests (in the sanctuary); this seems to be the meaning of the Septuagint.
(2) New Jerusalem Bible and Revised English Bible translate “at the dictation of the Levitical priests.”
(3) New Revised Standard Version has “in the presence of the Levitical priests.”
(4) New Jerusalem Bible has “written … by the Levitical priests,” with a footnote: “Nuance of Heb milliphne uncertain.”

It is recommended that the translation favored by Good News Translation and others be followed, namely, “from the original copy kept by the Levitical priests.” For Levitical priests see 17.9.

Quoted with permission from Bratcher, Robert G. and Hatton, Howard A. A Handbook on Deuteronomy. (UBS Helps for Translators). New York: UBS, 2000. For this and other handbooks for translators see here .