CORNERSTONE
It was the fundamental stone that constituted the exterior corner of a building. Stone located in the corner where two walls meet, keeping them together. Any stone that occupies this position from the base (Jb. 38:6; Is. 28:16) to the roof (Ps. 118:22; Zech. 4:7) is a cornerstone. Figuratively, Christ is the chief corner stone (Eph. 2:20; 1 Pet. 2:6), as well as the head of the corner (Mt. 21:42; 1 Pet. 2:7).