לַחֲכַם־לֵ֭ב יִקָּרֵ֣א נָב֑וֹן וּמֶ֥תֶק שְׂ֝פָתַ֗יִם יֹסִ֥יף לֶֽקַח׃
心中有智慧的，必被稱為聰明人；言語甜美，能使人增長學問。
Rashi
The wise-hearted shall be called understanding He who learned wisdom from his teacher.
Rashi
shall be called understanding. Ultimately, he will be understanding in matters and keen in his wisdom, and they will call him understanding.
Rashi
and the sweetness of speech increases learning When a person explains his words to a pupil and makes his words sweet with reasons, he increases learning.