for grinding corn, mentioned as used in the time of Abraham ( Genesis 18:6 ). That used by the Hebrews consisted of two circular stones, each 2 feet in diameter and half a foot thick, the lower of which was called the "nether millstone" ( Job 41:24 ) and the upper the "rider." The upper stone was turned round by a stick fixed in it as a handle. There were then no public mills, and thus each family required to be provided with a hand-mill. The corn was ground daily, generally by the women of the house ( Isaiah 47:1 Isaiah 47:2 ; Matthew 24:41 ). It was with the upper stone of a hand-mill that "a certain woman" at Thebez broke Abimelech's skull ( Judges 9:53 , "a piece of a millstone;" literally, "a millstone rider", i.e., the "runner," the stone which revolves. Compare 2 Samuel 11:21 ). Millstones could not be pledged ( Deuteronomy 24:6 ), as they were necessary in every family.