Amos 7:7

Amos saw a third vision. The Lord was standing beside a vertical wall with a plumb line in His hand. The wall was probably a city wall rather than the wall of a house. [Note: George Adam Smith, The Book of the Twelve Prophets Commonly Called the Minor, 1:114; Ellison, p. 66.] Niehaus believed Amos saw a wall of tin, symbolic of Assyria’s power, and the Lord standing above the wall judging it. [Note: Niehaus, p. 456. See also Chisholm, Handbook on . . ., pp. 397-98.] A plumb line was a string with a weight on the end. People used it, and still use it, to determine if a vertical structure is completely straight. God was testing something by a true standard; His judgment is not arbitrary.