Deuteronomy 27:2

And it shall be, on the day when you shall pass over Jordan ,.... Not the precise day exactly, but about that time, a little after they passed that river, as soon as they conveniently could; for it was not till after Ai was destroyed that the following order was put in execution; indeed as soon as they passed over Jordan, they were ordered to take twelve stones, and did; but then they were set up in a different place, and for a different purpose; see Joshua 4:3 ,

unto the land which the Lord thy God giveth thee, that thou shalt set thee up great stones ; not in Jordan, as Jarchi, but on Mount Ebal, Deuteronomy 27:4 ; nor had the stones set up in Jordan any such inscription as what is here ordered to be set on these:

and plaster them with plaster : that so words might be written upon them, and be more conspicuous, and more easily read.