Uncircumcised ear / Closed ears
A deaf or closed ear unwilling to listen. Figuratively: stubbornness (the root "arel" originally means sealed or closed).
("To whom shall I speak and testify, that they may hear? Behold, their ear is uncircumcised, and they cannot listen; behold, the word of the Lord has become to them a reproach, they have no delight in it." – Jeremiah 6:10; also: "Whatever attempts are made to persuade him… the words fall on deaf ears." – H. Be’er / Feathers, p. 25)
Translation
Expression (Hebrew)
אֹזֶן עֲרֵלָה, אוֹזְנַיִם עֲרֵלוֹת, אוזן ערלה
Definition (Hebrew)
אֹזֶן אֲטוּמָה שֶׁאֵינָהּ מוּכָנָה לְהַאֲזִין. בְּהַשְׁאָלָה: עַקְשָׁנוּת (עָרֵל בַּמָּקוֹר מַשְׁמָע אָטוּם, סָגוּר).
("עַל מִי אֲדַבְּרָה וְאָעִידָה וְיִשְׁמָעוּ הִנֵּה עֲרֵלָה אָזְנָם וְלֹא יוּכְלוּ לְהַקְשִׁיב הִנֵּה דְבַר ה' הָיָה לָהֶם לְחֶרְפָּה לֹא יַחְפְּצוּ בוֹ" - יִרְמְיָה ו י, כֵּן: "כָּל מָה שֶׁמְּנַסִּים לשדלו... נוֹפְלִים הַדְּבָרִים עַל אָזְנַיִם ערלות" - ח. בְּאֵר / נוֹצוֹת, 25)