He only is my rock ... - See the notes at Psalms 18:2.
I shall not be greatly moved - The word greatly here, or much - “I shall not be much moved,” implies that he did not anticipate perfect security from danger or calamity; he did not suppose that he would escape all disaster or trouble, but he felt that no great evil would befall him, that his most important interests were safe, and that he would be ultimately secure. He would be restored to his home and his throne, and would be favored with future peace and tranquility. None of us can hope wholly to escape calamity in this life. It is enough if we can be assured that our great interests will be ultimately secured; that we shall be safe at last in the heavenly world. Having that confidence the soul may be, and should be, calm; and we need little apprehend what will occur in this world.