לֹֽא־יַחְפֹּ֣ץ כְּ֭סִיל בִּתְבוּנָ֑ה כִּ֝֗י אִֽם־בְּהִתְגַּלּ֥וֹת לִבּֽוֹ׃
미련한 자는 명철을 기뻐하지 아니하고 자기의 의사를 드러내기만 기뻐하느니라
Tov haLevanon
The term "fool" applies to a man who is able to understand with his faculties, however, he does not want to toil but instead seeks comfort, as in "the fool does not desire understanding" (Mishlei 18:2), this is what the verse says: "the toil of the fool" - meaning the toil that the fool fears from and instead chooses comfort for himself.
Rabbeinu Yonah
A safeguarding fence around wisdom is silence: This is a safeguarding fence for both wisdom itself and for its traits. How is it? That he doesn't interrupt the words of his fellow, and he says about that we has not heard, "I have not heard." And even though it is not included in silence, silence brings to it. With wisdom, how is it? He does not speak in front of someone greater than him in wisdom. As one who studies in front of his teacher and sees a fit rationale should not immediately think that it is true; and he should not want to say it until his teacher has finished speaking. For were he to do so, he would miss what his teacher will say and he will not know the rationales of the earlier sages; as his heart will be 'moving and wandering from knowing their opinion.' And also because his [own] rationale cannot be so focused until he hears what the early scholars said and [then] weigh in the scales of his intellect which one is more proper - this one or that one. Therefore silence for a student in front of his teacher "is a safeguarding fence for wisdom." And when he finds a rationale and his teacher is still speaking, should he not be quiet? He should not open his mouth until the words of his teacher are clear and his rationale is etched into his heart - until he finishes his words and knows what his teacher taught him. And afterwards, his reasoning will be sharp and focused. And about this Shlomo, peace be upon him, said (Proverbs 18:2), "The fool does not desire understanding, but only to reveal his heart."