*Minor differences ignored. Grouped by changes, with first version listed as example.
And the Levites shall speak, and say unto all the men of Israel,.... Rather, "answer (e) and say"; not the whole tribe of Levi, for that stood on Mount Gerizim to bless, Deuteronomy 27:12; but the priests of that tribe who were placed in the valley, between the two mountains, and pronounced both the blessings and the curses in the hearing of all the tribes of Israel, to which they were to answer Amen; and that they might plainly hear, they expressed their words
with a loud voice, clearly and distinctly, as follow.
(e) "respondebunt", Montanus.
"And the Levites shall lift up and speak to all the men of Israel with a high (loud) voice:" i.e., they shall pronounce the different formularies of blessing and cursing, turning towards the tribes to whom these utterances apply; and all the men of Israel shall answer "Amen," to take to themselves the blessing and the curse, as uttered by them; just as in the case of the priestly blessing in Numbers 5:22, and in connection with every oath, in which the person swearing took upon himself the oath that was pronounced, by replying "Amen." "The Levites" are not all the members of the tribe of Levi, but those "in whom the spiritual character of Levi was most decidedly manifested" (Baumgarten), i.e., the levitical priests, as the guardians and teachers of the law, and those who carried the ark of the covenant (Joshua 8:33). From the passage in Joshua, where the fulfilment of the Mosaic injunctions is recorded, we learn that the Levitical priests stationed themselves in the centre between the two mountains, with the ark of the covenant, and that the people took up their position, on both sides, opposite to the ark, viz., six tribes on Gerizim, and six on Ebal. The priests, who stood in the midst, by the ark of the covenant, then pronounced the different formularies of blessing and cursing, to which the six tribes answered "Amen." From the expression "all the men of Israel," it is perfectly evident that in this particular ceremony the people were not represented by their elders or heads, but were present in the persons of all their adult men who were over twenty years of age; and with this Joshua 8:33, when rightly interpreted, fully harmonizes.
The Levites - Some of the Levites, namely, the priests, who bare the ark, as it is expressed Joshua 8:33, for the body of the Levites stood upon mount Gerizzim, Deuteronomy 27:12. But these stood in the valley between Gerizzim and Ebal, looking towards the one or the other mountain as they pronounced either the blessings or the curses.
*More commentary available at chapter level.