Psalms 55:4

4.My heart trembles within me (299) Here we have additional evidence of the extremity of David’s sufferings. He that uses these words was no soft or effeminate person, but one who had given indubitable proofs of constancy. Nor is it merely of the atrocious injuries inflicted upon him by his enemies that he complains. He exclaims that he is overwhelmed with terrors, and thus acknowledges that his heart was not insensible to his afflictions. We may learn from the passage, therefore, not only that the sufferings which David endured at this time were heavy, but that the fortitude of the greatest servants of God fails them in the hour of severe trial. We are all good soldiers so long as things go well with us, but when brought to close combat, our weakness is soon apparent. Satan avails himself of the advantage, suggests that God has withdrawn the supports of his Spirit, and instigates us to despair. Of this we have an example in David, who is here represented as struggling with inward fears, as well as a complication of outward calamities, and sustaining a sore conflict of spirit in his application to the throne of God. The expression, terrors of death, shows that he was on the very eve of sinking unless Divine grace interposed.