Psalms 55:5

Fearfulness and trembling - Fear so great as to produce trembling. Compare the notes at Job 4:14. He knew not when these things would end. How far the spirit of rebellion had spread he knew not, and he had no means of ascertaining. It seemed as if he would be wholly overthrown; as if his power was wholly at an end; as if even his life was in the greatest peril.

And horror hath overwhelmed me - Margin, as in Hebrew, “covered me.” That is; it had come upon him so as to cover or envelop him entirely. The shades of horror and despair spread all around and above him, and all things were filled with gloom. The word rendered “horror” occurs only in three other places; - Ezekiel 7:18, rendered (as here) “horror;” Job 21:6, rendered “trembling;” and Isaiah 21:4, rendered “fearfulness.” It refers to that state when we are deeply agitated with fear.