Мусар к Кохелет 11:9

שְׂמַ֧ח בָּח֣וּר בְּיַלְדוּתֶ֗יךָ וִֽיטִֽיבְךָ֤ לִבְּךָ֙ בִּימֵ֣י בְחוּרוֹתֶ֔ךָ וְהַלֵּךְ֙ בְּדַרְכֵ֣י לִבְּךָ֔ וּבְמַרְאֵ֖י עֵינֶ֑יךָ וְדָ֕ע כִּ֧י עַל־כָּל־אֵ֛לֶּה יְבִֽיאֲךָ֥ הָאֱלֹהִ֖ים בַּמִּשְׁפָּֽט׃

Радуйся, юноша, в юности твоей; И пусть сердце твое приветствует тебя во дни юности твоей, и ходи путями сердца твоего, и пред глазами твоими, Но знай, что за все это Бог приведет тебя на суд.

Kav HaYashar

From this incident we learn that a man must perceive clearly with his mind’s eye that the end of everything is to fear punishment and to recall continually the verse with which Shlomo concludes the book of Koheles. That is: “The end of the matter, when everything is heard, is to fear God and keep His commandments, for that is the entirety of a man” (Koheles 12:13). Shlomo adds: “And know that God will bring everything to judgment” (Koheles 11:9). The Sages tell us that if a person says that the Holy One Blessed is He disregards anything, Heaven will disregard his life (Bava Kama 50a). May these words be bound and sealed upon your heart. Then all will be well with us, selah.