Commentaries:
Landmarks are usually nocturnal creatures. When they move, they frequently do so at night, secretly.
The protection of boundary markers provided by God's law bespeaks the propriety of the private ownership of property. When wandering in the wilderness, the Israelites owned no land. Boundaries had no real significance to them, aside from the boundary of the camp at large. Now, coming into inheritance of the Promised Land, and its concomitant subdivision among the tribes, the sanctity of boundary markers becomes vital to the efficient and peaceful functioning of society.
The ongoing use of land obtained by the subterfuge of clandestinely moving landmarks is a superb image of “doing a lie”(Revelation 22:15)—that is, living a lie. As such, it is an image of hypocrisy. Those who make use of land not theirs by falsifying boundaries might well benefit from the theft for generations. (For more details, see Deuteronomy 19:14.)
Charles Whitaker
Unity and Division: The Blessing and the Curse (Part Four)
Looking at the underlying commonality of the Ebal-curses—that they focus on secret sin—we may conclude that the six tribes on Ebal represent those church members whom we could call “wolves in sheep's clothing,” in whom God finds unrepented sin, individuals living a secret life, closeted in some way, hypocrites.
Conversely, we may conclude that the six tribes atop Mount Gerizim symbolize those people in God's church who exhibit sincerity and wholeness of heart, unwavering commitment to keeping the principle inherent to the Feast of Unleavened Bread—and, by extension, living their entire lives—“not with the old leaven, the leaven of malice and evil, but with the unleavened bread of sincerity and truth” (I Corinthians 5:8).
Those on Gerizim, unlike their fellows on the Mount of Cursing, represent individuals who break their bread with “singleness of heart” (Acts 2:46), fully committed to abandoning all sin, no matter how stubbornly closeted it may have been at one point in their lives, no matter how tenacious its addiction, no matter how much carnal pleasure it might bring. On Gerizim stand, symbolically, those of God's people who, recognizing the damnation of the charade, have firmly rejected living a double-life. Those who so shun sham and find no pleasure in the mask really do stand on the Mountain of Blessing!
Charles Whitaker
Unity and Division: The Blessing and the Curse (Part Five)