The sages loved to measure the enemies of Israel, because their sheer size made the victory more astonishing. When Sennacherib the Assyrian invaded Judah, he came with forty-five thousand princes in golden coronets, each riding with his household, his wives, and his consorts. Running before him were eighty thousand armored warriors and sixty thousand swordsmen. The rest of the army was cavalry.
The tradition reports that an identical army once came against Abraham in the war of the kings (Genesis 14), and a third force of the same size will one day march with Gog and Magog in the final battle of the end of days.
The numbers they assign are staggering. The camp stretched four hundred parsaot, a league being roughly three miles. The horses stood so tightly packed that their necks together measured forty parsaot. The total muster, the sages calculated, came to two hundred and sixty myriads of thousands, less one. Abaye, always the careful reader, asked, "Less one what? One myriad? One thousand? One hundred? Or literally one single soldier?" The tradition leaves the question open (Sanhedrin 95b).
The larger point is not the arithmetic. It is that the enemy who came against Jerusalem in Hezekiah's day, the enemy Abraham faced at Dan, and the enemy waiting at the end of history are, in the sages' eyes, one long line of the same army. And each time, the Holy One has already written the ending.