Ecclesiastes 1:4 - Matthew Poole's English Annotations on the Holy Bible

One generation passeth away, and another generation cometh: men continue but for one, and that a short age, and then they leave all their possessions to the succeeding age; and therefore they cannot be happy here, because happiness must needs be unchangeable and eternal; or else the perpetual fear and certain knowledge of the approaching loss of all these things will rob a man of all solid contentment in them. The earth abideth for ever, i.e. through all successive generations of men; and therefore man in this respect is more mutable and miserable than the very earth upon which he stands; and which, together with all the glories and comforts which he enjoyed in it, he leaveth behind him to be possessed by others.