Musar su Ecclesiaste 6:6

It is well-known that this world is all emptiness, that every amusement is worthless, and woe is anyone who pursues vanity, which is worthless. And don't envy the rich, for "riches are hoarded by their owner to his misfortune" (Koheles 5:12); "As he had come from his mother's womb, naked will he return...exactly as he came he must depart, and what did he gain by toiling for the wind?" (ibid. 14, 15); "Even if he should live a thousand years twice over, but find no contentment - do not all go to the same place?" (Ib. 6:6); "Even if man lives many years, let him rejoice in all of them, but let him remember that the days of darkness will be many. All that comes is futility" (ib. 11:8); "And of joy, what does it accomplish?" (ibid. 2:2). Tomorrow you will cry for having laughed today. Do not lust after imaginary honor, for it is worthless and time is a traitor: it is like scales, which lift the light and lower the weighty. The world is like one who drinks salty water: he thinks it quenches his thirst, but it only makes him thirstier. No one leaves the world with even half his cravings fulfilled (Koheles Rabbah 1). "What profit does one have from all his toils under the sun" (Koheles 1:3)? Remember our predecessors, all of whose love, desire and joy have ceased to exist (see Koheles 9:6), but who are being judged severely for them. And of what benefit is gratification to man - whose end is dust, maggots and worms, as he is bound to die - when all his enjoyments turn to bitterness in the grave? And what is this world, whose days are full of anguish and pain which prevent one from sleeping? Neither is death a mikveh. Man will be judged for everything he says; even the slightest expression is not overlooked.

Concerning man we are told in Kohelet 6,6, ואלו חיה אלף שנים פעמים, "if he had lived a thousand years twice, etc." The wording we would have expected would have been: "if he had lived two thousand years, etc." Why this peculiar wording? There are three levels at which life is lived, i.e. מעשה, דבור, מחשבה, and man has been equipped with נפש, רוח, נשמה, which can be termed as עשיה, יצירה, בריאה, to enable him to live his life at these various levels, as we know from the Zohar and the book Reyshit Chochmah, both of which explain this at length. The spiritual aspect of מעשה, deed, is related to נפש, whereas the spiritual aspect of דבור=study, is related to רוח, i.e. the world of יצירה. Finally, the spiritual aspect of מחשבה relates to the spheres of בריאה and נשמה, something still further removed from anything physical, tangible. The latter, i.e. the נשמה is destined to return to its origin under the כסא of G–d, whence it had been taken prior to entering a human body. A select few can reach the sphere of מחשבה דמחשבה, the region of נפש, רוח, נשמה of the עולם האצילות.

In other words, such people penetrate to one half of the ribotayim mentioned in Psalms 68,18. This is why the verse in Psalms 91,7 is quoted, since it speaks of revavah =ten thousand, instead of rivotayim, twenty thousand. The meaning of Kohelet 6,6, in which even twice a lifetime of one thousand years is described as ultimately futile, is that unless one achieves רבבה, the level of עולם הבריאה, one has failed to achieve one's goal, i.e. half the “full yud.”