A "heart of stone" denotes great insensibility (1-Sam 25:37).
Stones were set up to commemorate remarkable events, as by Jacob at Bethel (Gen. 28:18), at Padan-aram (35:4), and on the occasion of parting with Laban (31:45); by Joshua at the place on the banks of the Jordan where the people first "lodged" after crossing the river (Josh. 6:8), and also in "the midst of Jordan," where he erected another set of twelve stones (4:1); and by Samuel at "Ebenezer" (1-Sam 7:12).