(Isa. 3:26)
Sitting on the ground was a posture which denoted deep distress. When Job’s friends came to sympathize with him, “they sat down with him upon the ground seven days and seven nights, and none spake a word unto him: for they saw that his grief was very great” (Job 2:13). When the Jews were in captivity, it is said, “By the rivers of Babylon, there we sat down, yea, we wept, when we remembered Zion.” (Ps. 137:1). Jeremiah also alludes to the same custom in Lam. 2:10; 3:28. The same idea is represented in a more intensified form in the expressions, “wallow thyself in ashes” (Jer. 6:26), and “roll thyself in the dust” (Micah 1:10).
Most of the Roman coins which were struck in commemoration of the capture of Jerusalem have on one side the figure of a woman sitting on the ground… . The figure is generally represented with one hand to the head, which rests upon it inclining forward, and the other hanging over the knee, thus presenting a picture of great grief. In one instance, however, the hands are tied behind the back.
(James M. Freeman, Manners and Customs of the Bible [Plainfield, New Jersey: Logos International, 1972], 254–55.)