Ezekiel 42:20

42:20 He measured it on the four sides: it had a wall round about, the length five hundred, and the breadth five hundred, to make a separation between that which was holy and that which was common.
-World English Bible

Other Translation

42:20 He measured it by the four sides: it had a wall round about, five hundred [reeds] long, and five hundred broad, to make a separation between the sanctuary and the profane place.
-King James Version