He who takes care of public matters forgets his study.
A person who is busy dealing with public action may forget what he has learned.
("He who takes care of public matters forgets his study" – Shemot Rabbah (Vilna edition), Parashat Va'era, 6)
Translation
Expression (Hebrew)
הַמִּתְעַסֵּק בְּצָרְכֵי צִבּוּר מְשַׁכֵּחַ תַּלְמוּדוֹ
Definition (Hebrew)
מִי שֶׁמַּעֲדִיף לְהִתְרַכֵּז בָּעֲשִׂיָּה עָלוּל לִשְׁכֹּחַ אֶת הַדְּבָרִים שֶׁלָּמַד.
("הַמִּתְעַסֵּק בְּצָרְכֵי צִבּוּר מְשַׁכֵּחַ תַּלְמוּדוֹ" – שְׁמוֹת רַבָּה (וִילְנָה) וָאֵרָא פָּרָשָׁה ו)