Bible Dictionary
FOURSQUARE
Foursquare means equal in length and breadth, forming a square or having four equal sides. Scripture applies the shape to altars, sacred furnishings, courts, and the New Jerusalem.
Biblical Usage
Scripture applies foursquare form to the altar of burnt offering, the altar of incense, the high priest’s breastplate, temple panels, Ezekiel’s court and holy oblation, and the New Jerusalem in John’s vision. In these descriptions, the shape conveys perfect symmetry.