Revelation 21:12

Twelve gates] 'Four is the number which is the symbol of the world, three that of God. Twelve, therefore, is the signature of the covenant people among whom God dwells. The enclosure of the Tabernacle was a square space, three tribes being over against each of the four sides. Thus we have a square with the Tabernacle in the midst, expressive of God in. the midst of His people' (Currey).