:I suppose that you refer to the Psalms 91:6, which in King James is translated as "Nor for the pestilence that walketh in darkness; nor for the destruction that wasteth at noonday." 
 :I am not a true expert in the Biblical language and it is a very hard verse. It is a verb, and it's an ancient form that is only used in the Bible once and not used in the modern language at all (in the modern language it is ישדוד - yišdod). It means "destroying" or "will destroy"; maybe in context it means "that will destroy", but the word "that" doesn't appear in the original and is added by the translators into English - that's why in translations it is often written in an italic font. The word "that" is often omitted in Biblical poetry, but you need a serious Bible expert to say where it should and should not be, and even experts need to guess sometimes. 
 :I hope it helped.