"Though a host should encamp against me, my heart shall not fear: though war should rise against me, in this will I be confident." (Psalm 27:3)
In "Word Focus" Danny McCain writes:
The word confident in verse 3 sheds some insight into why the psalmist was not afraid. It is the word batach which “expresses that sense of well-being and security which results from having something or someone in whom to place confidence” (Theological Wordbook of the O.T.). The word does not seem to have the basic connotation of “faith” in the evangelical sense. Rather it describes a feeling of security and safety. It is used in Judges 18:7: “Then the five men departed, and came to Laish, and saw the people that were therein, how they dwelt . . . quiet and secure.”
Source: Studies in the Psalms: Adult Teacher's Insights, page 22.