ציטירנדיקער פּירוש אויף דברים 33:4

Kohelet. This refers to the concept of gathering and collecting, like the congregation of Jacob (Deuteronomy 33:4), and King Solomon was referred to [as Kohelet], because he gathered the conflicting opinions to merge and clarify the correct from the incorrect:

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Koheles. [He was called Koheles] because he gathered [=קִהֵל much wisdom,¹¹The term קהלת meaning gathering is in Devarim 33:4 where it states, “the gathering [קהלת] of Yaakov.” (Metsudas Tzion) and similarly, elsewhere [Scripture] calls him, “Agur Bin Yokeh,”¹²Mishlei 30:1. This is a reference to Shlomo, meaning the gatherer [אגור] of wisdom [בן] spewed out [יקה] the prophecy [המשא]. because he gathered אָגַר all the wisdom and spewed וַהֲקִיאָהּ it out, and some say that he would say all his words in public assembly [=בְּהַקְהֵל.¹³Alternatively, he gathered together and clarified many conflicting views. (Metsudas Tzion)