Preaching And Reading The Old Testament Lessons
If we look at the context of the passage, the words that immediately precede and follow it announce judgment upon Judah at the hands of the Lord because of Judah's lack of faith. In the eighth century B.C., that which God repeatedly asks of his people through the words of Isaiah is trust, trust that their lives are in God's hands and that he will preserve them, no matter what enemy is attacking them.
For thus said the Lord God, the Holy One of Israel,
In returning and rest you shall be saved;
in quietness and in trust shall be your strength.