Deuteronomy 27:11

“And Moses charged the people the same, etc.] That he gave the above orders to set up stones, and plaster them, and write the law on them, and build an altar in the same place, and offer sacrifices when come into the land of Canaan: saying; as follows.”

“THE TRIBES DIVIDED ON GERIZIM AND EBAL. (Deu 27:11-13) These shall stand upon mount Gerizim to bless the people . . . these shall stand upon mount Ebal to curse--Those long, rocky ridges lay in the province of Samaria, and the peaks referred to were near Shechem (Nablous), rising in steep precipices to the height of about eight hundred feet and separated by a green, well-watered valley of about five hundred yards wide. The people of Israel were here divided into two parts. On mount Gerizim (now Jebel-et-Tur) were stationed the descendants of Rachel and Leah, the two principal wives of Jacob, and to them was assigned the most pleasant and honorable office of pronouncing the benedictions;…”

“Compare Joshua 8:32-35. The solemnity was apparently designed only for the single occasion on which it actually took place. Deuteronomy 27:12, Deuteronomy 27:13 The tribes appointed to stand on Gerizim to bless the people all sprang from the two wives of Jacob, Leah and Rachel. All the four tribes which sprang from the handmaids Zilpah and Bilhah are located on Ebal. But in order, as it would seem, to effect an equal division, two tribes are added to the latter from the descendants of the wives, that of Reuben, probably because he forfeited his primogeniture Genesis 49:4; and of Zebulun, apparently because he was the youngest son of Leah. The transaction presents itself as a solemn renewal…”

“With the solemn erection of the stones with the law written upon them, Israel was to transfer to the land the blessing and curse of the law, as was already commanded in Deu 11:29; that is to say, according to the more minute explanation of the command which is given here, the people themselves were solemnly to give expression to the blessing and the curse: to the former upon Mount Gerizim, and to the latter upon Ebal. On the situation of these mountains, see at Deu 11:29. To this end six tribes were to station themselves upon the top or side of Gerizim, and six upon the top or side of Ebal. The blessing was to be uttered by the tribes of Simeon, Levi, Judah, Issachar, Joseph, and Benjamin,…”