Revelation 21:16 - Ellicott's Commentary On The Whole Bible

And the city lieth foursquare... — The city is foursquare, because the length and breadth are equal; but it is added that the height also is equal to the length and breadth, the city thus presents the symbol of perfect symmetry; this is all that is needed. Many interpreters are nervously anxious about the monstrous appearance of a city whose walls measured three thousand stadii (the word rendered “furlongs” is properly stadii); but there is no need to be nervous about the symbols; the city is not designed, any more than the vision of Revelation 4, or the vision of Ezekiel (Ezekiel 1) to be represented by painting to the eye: the attempt to do so only ends in the production of grotesque and profane pictures. It is not needful, however, in this case to suppose the actual wall to have been 3,000 stadii in height; the city is placed on a hill, the foundations are upon the holy hill, and the deep strong mountain foundations may be included in the measurement. The main thought, however, is to realise the harmony and proportion of that community, in which broad and low and high will meet, and in which no truth will be exaggerated or distorted; in which no disproportioned adjustments will mar its social order; in which all those who are inbuilt as living stones will be measured, not by the false estimates of worldly thoughts (comp. James 2:4), but by the golden reed of the sanctuary.