Ecclesiastes 6:4 Kabbalah

כִּֽי־בַהֶ֥בֶל בָּ֖א וּבַחֹ֣שֶׁךְ יֵלֵ֑ךְ וּבַחֹ֖שֶׁךְ שְׁמ֥וֹ יְכֻסֶּֽה׃

for it cometh in vanity, and departeth in darkness, and the name thereof is covered with darkness;

Read kabbalistic (mystical) interpretation of Ecclesiastes 6:4: and classical mystical sources.