Jamieson, Fausset and Brown on Deuteronomy 27:2

CHAPTER 27

De 27:1-10. The People Are to Write the Law upon Stones.

2. it shall be on the day when ye shall pass over Jordan--"Day" is often put for "time"; and it was not till some days after the passage that the following instructions were acted upon.

thou shalt set thee up great stones, and plaister them with plaister--These stones were to be taken in their natural state, unhewn, and unpolished--the occasion on which they were used not admitting of long or elaborate preparation; and they were to be daubed over with paint or whitewash, to render them more conspicuous. Stones and even rocks are seen in Egypt and the peninsula of Sinai, containing inscriptions made three thousand years ago, in paint or plaister. By some similar method those stones may have been inscribed, and it is most probable that Moses learned the art from the Egyptians.