16 they are the ones who will dwell on the heights, whose refuge will be the mountain fortress. Their bread will be supplied, and water will not fail them.

Read Isaiah 33:16 Using Other Translations

He shall dwell on high: his place of defence shall be the munitions of rocks: bread shall be given him; his waters shall be sure.
he will dwell on the heights; his place of defense will be the fortresses of rocks; his bread will be given him; his water will be sure.
these are the ones who will dwell on high. The rocks of the mountains will be their fortress. Food will be supplied to them, and they will have water in abundance.