John Gill Commentary Ezekiel 48:17

"And the city shall have suburbs: toward the north two hundred and fifty, and toward the south two hundred and fifty, and toward the east two hundred and fifty, and toward the west two hundred and fifty." — Ezekiel 48:17 (ASV)

And the suburbs of the city shall be toward the north two
hundred and fifty
That is, so many reeds: and toward the south two hundred and fifty ;
which make five hundred; and these being added to four thousand five hundred, north and south, make five thousand: and toward the east two hundred and fifty, and toward the west two
hundred and fifty ;
which being added to four thousand five hundred, east and west, make five thousand; and so an equilateral square on each side, length and breadth.