פִּֽי־כְ֭סִיל מְחִתָּה־ל֑וֹ וּ֝שְׂפָתָ֗יו מוֹקֵ֥שׁ נַפְשֽׁוֹ׃
La bouche du sot cause sa ruine, et ses lèvres sont un piège pour sa personne.
Akeidat Yitzchak
Rabbi Yannai in the opening Midrash quoted, simply wanted to tell us that the lesson taught by the spice merchant had already been taught by Solomon in Proverbs.