פירוש על קהלת 6:12

For who knows. For who knows good deeds and what man should do during his life, so that it will bring him goodness in the hereafter.

“For who knows what is good for man in his life, all the days of his life of vanity, that he spends like a shadow? For who can tell man what will be after him under the sun?” (Ecclesiastes 6:12).
“For who knows what is good for man in his life” – Rabbi Huna [said] in the name of Rabbi Aḥa: David made a statement and did not explain it, but his son Solomon explained it. Solomon made a statement and did not explain it, but his father David explained it. Solomon said: “For who knows what is good for man in his life… that he spends like a shadow?” How so? If you say it is the shadow of a wall, it has substance. If it is the shadow of a palm tree, it has substance. David came and explained: “His days pass like a shadow” (Psalms 144:4). David made a statement and did not explain it, but his son Solomon explained it. David said: “Man is like hevel” (Psalms 144:4); to what hevel [is man compared]? If it is to the hevel [heat] of an oven, it has significance. If it is to the hevel of a stove, it has significance. His son Solomon came and explained: “Vanity of vanities [havel havalim] said Kohelet” (Ecclesiastes 1:2).
Another matter, “for who knows what is good for man in his life” – Rabbi Pinḥas said: Since the days of man are vanity, and they are numbered, and they are like a shadow, what pleasure does one have in life? Rather, let them engage in matters of Torah, which are all life. “For who can tell man [what will be after him under the sun?]” – Solomon said, I will tell you what is better than them all: “A good name is better that fine oil” (Ecclesiastes 7:1).

In the counted days of his vanity. Which are limited in number