Ecclesiastes 8:13 - Matthew Poole's English Annotations on the Holy Bible

It shall not be well, i.e. it shall go very ill with him; great miseries are prepared for him; which is a figure oft used in Scripture, as hath been formerly and frequently observed. Neither shall he prolong his days, to wit, very long, or for ever, as he desireth. As a shadow; his life, though it may be or seem to be long, yet in truth is but a mere shadow, which will quickly vanish and disappear, and be as if it never had been; and many times, like a shadow, when it is longest, it is nearest to abolition. Because he feareth not before God; this is the punishment of his wickedness, and his casting off the fear and service of God. For although the lives of good men upon earth are short, as well as the lives of the wicked, yet their days are not like a shadow, because they are prolonged far beyond this mortal state, even to all eternity, and death itself doth but open the way for them to an endless life.