'Assembling' in the Bible

And the satraps, the prefects, the governors and the advisors of the king [were] assembling, [and] they saw these men, that the fire had no power over their bodies, and the hair of their heads was not singed, and their garments were not harmed, and the smell of fire did not come from them.

His sons will prepare for war, assembling an army of considerable force. One of them will come on forcefully, overflowing, passing through, and waging war up to his own fortress.