I. On Ebal the altar was raised (Deut. 27, v. 5; and here, v. 30), not on Gerizim. First: Because there ought to be one altar. Secondly: Because perhaps the Lord then already willed to deprive the future temple of the Samaritans on Gerizim of an altar, as if that temple were empty and void.
II. On Gerizim were these six tribes: Simeon, Levi, Judah, Issachar, Joseph (or Ephraim), and Benjamin. But on Ebal, Reuben, Gad, Asher, Zebulun, Dan, Naphtali (Deut. 27, vv. 12, 13). The Rabbis give the cause: because the first six were the sons of free wives; the rest [were sons] either of handmaids, or certainly the last-born of the free [wives].
III. In the cited chapter of Deuteronomy these tribes are said to have been “upon” [super] those mountains, but here (v. 33) “beside” [iuxta]. But the Hebrew particle “hal” [ʿal] can be rendered “upon,” “beside,” and “in.” Now part of them was at the root of the mountains, nearly beside the priests, who were in the lowest valley; but part on the upper ridge of the mountains; and these are said to have been “upon,” those “beside” the mountains. Surely [those] who were beside the mountains, and as it were opposite [them], are described here to have been the “elders [and] leaders” — who in the Hebrew [are] “schoterim” [officers], concerning whom before (ch. 1) — and the “Judges.” But they did not sit, but — as [it is] in the same place of Deuteronomy — “they stood,” by which, namely, a greater and more religious attention, veneration, and reverence might be signified. But it is not to be doubted that, in a good and beautiful order, the six tribes of each mountain, and the families and houses of the tribes — the women, boys, and girls — were arranged: so that there was there no ἀταξία [ataxia, disorder], no disturbance, levity, or wantonness; nay, [there was] not even any danger from enemies, if perchance any should rush in from elsewhere.
(col. 945)