Eccl. 2:16.  For of the wise man as of the fool there is no enduring remembrance, seeing that in the days to come all will have been long forgotten.

What the wise man has decided and established by his own counsels as well as what the fool has done by his temerity, whether it turned out well or badly, will be consigned to oblivion. For neither they themselves nor others become better, so that they commit everything to God; but their descendants follow their own counsels and are not content with the ordinances of their ancestors but look for new ones. They are tired of what they have, and they look for what they do not have. This is what they imagine: “If it succeeded before, it will succeed again. If it did not succeed, it will succeed now. We will act more wisely than they did.” Look at the Roman republic, how the consuls and emperors who followed always revoked what had been done by those who had preceded them; they were bored with the present and the past, and they looked to the future. Why then do you afflict yourself with many cares, as though your descendants were going to approve of what you are doing or even were going to feel the same way? They will not, for whatever one has one despises as useless. Therefore it is impossible for things or constitutions to remain in the same esteem among the descendants that they had among the ancestors. Lycurgus thought that he had given laws to the Lacedemonians that they would keep until he returned, that is, forever. With this in mind he departed never to return, hoping for the future and supposing that in this way his laws would be perpetuated. But he accomplished nothing. Augustus used to say that he had laid such foundations for the state that he hoped it would stand forever, but those who followed soon overthrew it all. (Luther’s Works, v.15 p.42-43)

Eccl. 2:15.  Then I said to myself: What befalls the fool will befall me also; why then have I been so very wise? And I said to myself that this also is vanity.

This, too, is intended to make us refrain from trust in our own counsels. “I administered my kingdom very wisely,” he says, “and yet it did not succeed as I wished. On the other hand, I had a prefect who did not rule as wisely, and yet he did succeed. Therefore when I see that fools have almost the same success or even greater success, why have I made such an effort to act wisely? That is, why do I trust in my own counsels and my own wisdom, adding sorrow to labor? And I said to myself that this also is vanity. By my experience I learned that one should trust neither in counsel nor in temerity.” Earlier it was shown that wisdom excels folly, even though affairs are decided neither by folly nor by wisdom. One should, therefore, travel by the middle way: affairs should be commended to the King, who has made us. If He has granted us some opportunity, let us use it; if He has given us something, let us accept it; if He takes it away, let us bear it. Whatever you can do, do; whatever you cannot do, leave alone. What you cannot budge, let lie. Wisdom is beneficial, then, if I do what I know is pleasing to God and commit to Him what He wishes to be accomplished through me. If we did this, then at last we would be truly wise. (Luther’s Works, v.15 p.41-42)