(1) 'achar, "back side" as in the King James Version): "He led the flock to the back of the wilderness" (Ex 3:1), i.e. "to the pasture-lands on the other side of the desert from the Midianite encampments."
(2) 'achor, "hinder part," "the West"): Used of God in an anthropomorphic sense ("Thou shalt see my back," Ex 33:23) to signify "the after-glow of the Divine radiance," the faint reflection of God's essential glory. See also Isa 38:17 and compare 1Ki 14:9 and Ne 9:26.
(3) opisthen, "back side"): "A book written within and on the back" (Re 5:1), "but the back of a book is not the same as the reverse side of a roll. John was struck, not only with the fact that the roll was sealed, but also with the amount of writing it contained" (HDB, I, 231). Compare Eze 2:10.
M.O. Evans