“The devouring fire and everlasting burnings of verse 14 are clearly the emblems of the Divine Presence.  The Righteous dwell in God as the bush which was baptized in the shekinah-glory and was not consumed.  The fire of his holy presence makes them holy at the same time that it protects them from their enemies.  Compare with Psalm 15.  They are characterized by their walk, speech, the closed fist, the stopped ears, and the shut eyes.  They dwell in heights which are inaccessible to the foe, and no oppressor can cut off their supplies of hidden manna or water of life.  

Hezekiah, Isaiah predicts in verse 17, would soon put off his sackcloth, and the citizens would cease to be penned up in a beleaguered city.  They should recall the terror of that hour as a bad dream, recalled to be dismissed and forgotten.  Zion had no river, but God would be all that a river was to other cities, without the disadvantages of navigable water which might serve for the passage of a hostile fleet.  

Be sure to make God your Judge, Lawgiver, and King.  Then, notwithstanding that you limp in weakness, you shall gather your share in the great spoils of victory.” 

With these thoughts in mind, let me encourage you to again read over Isaiah 33:14-24.