John Wesley on Ecclesiastes 1:7

Is not full - So as to overflow the earth. Whereby also he intimates the emptiness of mens minds, notwithstanding all the abundance of creature comforts. Rivers come - Unto the earth in general, from whence they come or flow into the sea, and to which they return by the reflux of the sea. For he seems to speak of the visible and constant motion of the waters, both to the sea and from it, and then to it again in a perpetual reciprocation.