Deuteronomy 27:8
And thou shalt write upon the stones all the words of this law very plainly.
Cross-reference
Deuteronomy 27:3
Parallel
Deuteronomy 27:3 gives the same command to write the law on stones upon entering the land, reinforcing the instruction here.
Joshua 8:32
Prophetic fulfillment
Joshua 8:32 records the fulfillment: Joshua wrote a copy of the law on stones at Mount Ebal as commanded here.