Koheles 1:2

הֲבֵל הֲבָלִים אָמַר קֹהֶלֶת, הֲבֵל הֲבָלִים הַכֹּל הָבֶל

Vanity of vanities, says Koheles. Vanity of vanities, all is vanity.

Rather than translating the phrase “haveil havalim” as “vanity of vanities,” the Metzudas Dovid says that “haveil” is a verb. According to this interpretation, the message of Koheles is, “Recognize vanities and declare them to be such,” rather than ascribing importance to things that are ultimately just trivialities.