in which he teaches that as one becomes wiser, one discovers the clear language for simple folk
"Because Koheleth was a sage, he continued to instruct the people." This would seem to only be natural, for the more wisdom one amasses by increased study the more possibilities one has of teaching, having more Torah and wisdom to impart to students. In what sense, then, was Solomon praiseworthy in accumulating knowledge, having nevertheless taught the people? On the contrary. This is explained by the fact that there are scholars who the greater their Torah learning becomes and their wisdom increases find it difficult to teach the people. If they have a deep and detailed halakhic argument, they seek out the company of Torah scholars who can understand their words. The greatness of Koheleth, however, was in that as his wisdom increased, he turned to the people and taught the simple folk even more frequently, seeking the simple language that they could understand, to lead them in their right path and towards the right deeds.
Sha'arei Ezra, p. 34, Eliyahu Touffiq, ed., Beer Yehuda Yeshiva Press, Jerusalem 1996