Or HaChaim on Deuteronomy 27:3/אור החיים על דברים כ״ז:ג׳

1 למען אשר תבא אל הארץ "in order that you may enter the land, etc." Rabbi Avraham ibn Ezra explains this to mean that when you commence to observe His commandments, i.e. to inscribe the stones, (and this is the first commandment), you will enter the Holy Land by dint of this merit. Nachmanides understands the words: "in order that you will enter" as a commandment to inscribe the entire Torah on these stones at the time the Israelites would cross the Jordan [as opposed to Ibn Ezra who wrote that only the actual commandments had to be inscribed on these stones. Ed.] I do not believe that either one of these two explanations does justice to the plain meaning of our verse. Another thing we have to explain are the words כאשר דבר ה׳ אלוקי אבותיך לך, "as the Lord the G'd of your fathers has said to you." The Torah should have written the word לך, to you, immediately after the words כאשר דבר, and we would have entertained no doubt about who had said this to the Israelites.

2However, the Torah had to consider the fact that previously Moses had told the Israelites that the fact that they would enter the Holy Land was not due to their own merits (compare 9,5), but to the wickedness of the Canaanites residing in that land at that time. Another reason given by the Torah at that time for the Israelites entering and taking possession of the land was the promise G'd had made to their forefathers Abraham, Isaac and Jacob. In view of all this, the Torah here had to state that fulfilment of a commandment would be a factor in the Israelites entering the Holy Land due to their own מצוה-input. The positioning of the word לך at the end of the verse is an arbitrary decision by Moses, the author of our verse. The meter of the whole verse is as follows: "in order that your entry into the land which the Lord your G'd gives to you in accordance with what He said to your forefathers will be one which you are entitled to by your own merit, so that you do not have to rely on the covenant G'd made with your ancestors."