Matthew Henry on Psalms 91:9-16

Whatever happens, nothing shall hurt the believer; though trouble and affliction befal, it shall come, not for his hurt, but for good, though for the present it be not joyous but grievous. Those who rightly know God, will set their love upon him. They by prayer constantly call upon him. His promise is, that he will in due time deliver the believer out of trouble, and in the mean time be with him in trouble. The Lord will manage all his worldly concerns, and preserve his life on earth, so long as it shall be good for him. For encouragement in this he looks unto Jesus. He shall live long enough; till he has done the work he was sent into this world for, and is ready for heaven. Who would wish to live a day longer than God has some work to do, either by him or upon him? A man may die young, yet be satisfied with living. But a wicked man is not satisfied even with long life. At length the believer's conflict ends; he has done for ever with trouble, sin, and temptation.