He is not burned even by boiling water
He is not burned even by boiling water. Figuratively: someone who does not understand hints, not even the most obvious ones. Or: someone who is not offended even by a heavy insult. 'Thick-skinned'.
("It happened that the maidservant of Rabbi Eliezer died, and his disciples came to comfort him. When he saw them, he went up to the attic—and they followed him. He entered an inner room—they followed him, he entered the hall—they followed him. He said to them: I used to think you were burned by lukewarm water, but now I see you are not burned even by boiling water!" - Berakhot 16a)
Translation
Expression (Hebrew)
אֵינוֹ נִכְוָה אֲפִלּוּ בְּחַמֵּי חַמִּין
Definition (Hebrew)
אֵינוֹ נִכְוָה אֲפִלּוּ בַּמַּיִם רוֹתְחִים. בְּהַשְׁאָלָה: אֵינוֹ מֵבִין רְמָזִים, אֲפִלּוּ לֹא רְמָזִים עָבִים. אוֹ: אֵינוֹ נֶעֱלַב גַּם מֵעֶלְבּוֹן כָּבֵד. 'בַּעַל עוֹר שֶׁל פִּיל'.
("מַעֲשֶׂה וּמֵתָה שפחתו שֶׁל רַבִּי אֱלִיעֶזֶר נִכְנְסוּ תַּלְמִידָיו לנחמו. כֵּיוָן שֶׁרָאָה אוֹתָם עָלָה לעלייה- ועלו אַחֲרָיו. נִכְנָס לאנפילון- נִכְנְסוּ אַחֲרָיו, נִכְנָס לטרקלין- נִכְנְסוּ אַחֲרָיו. אָמַר לָהֶם: כמדומה אֲנִי שֶׁאַתֶּם נכוים בפושרים, עַכְשָׁו אִי אַתֶּם נכוים אֲפִלּוּ בְּחַמֵּי חַמִּין!"-בְּרָכוֹת טז ע"א)