His inside is not like his outside
His inner self is not like his outer self. By extension: his words and heart are not in accord. A liar or hypocrite who pretends (in Aramaic, 'bar' means exterior. 'Kevaro' means like his exterior).
(“It was taught: On that day they removed the doorkeeper and allowed the students to enter, for Rabban Gamliel would announce: Any student whose inside is not like his outside shall not enter the study house.” – Berakhot 28a. Also: “A flatterer – his inside is not like his outside, but he will not do evil openly.” – Malbim, Isaiah 10:6. Also: “The arrogant, the haughty, whose inside is not like their outside, behaving with deceit and cunning as is their way.” – Mendele / In Those Days. Also: “The eyes of the Judah family, always drawn to him, sense that his inside is not like his outside.” – Y. Burla / Longings, 155.)
Translation
Expression (Hebrew)
אֵין תּוֹכוֹ כְּבָרוֹ
Definition (Hebrew)
פְּנִימִיּוּתוֹ אֵינָהּ כְּמוֹ חִיצוֹנִיּוּתוֹ. בְּהַשְׁאָלָה: פִּיו וְלִבּוֹ אֵינָם שָׁוִים. שַׁקְרָן אוֹ צָבוּעַ הַמַּעֲמִיד פָּנִים (בַּר מִשְׁמָעוֹ בַּאֲרָמִית חִיצוֹנִיּוֹת. 'כְּבָרוֹ' מַשְׁמָע כְּמוֹ הַחִיצוֹנִיּוּת שֶׁלּוֹ).
("תַּנָּא: אוֹתוֹ הַיּוֹם סַלְּקוּהוּ לְשׁוֹמֵר הַפֶּתַח וּנְתָנָהּ לָהֶם רְשׁוּת לְתַלְמִידִים לִכָּנֵס. שֶׁהָיָה רַבָּן גַּמְלִיאֵל מַכְרִיז וְאוֹמֵר: כָּל תַּלְמִיד שֶׁאֵין תּוֹכוֹ כְּבָרוֹ - לֹא יִכָּנֵס לְבַיִת הַמִּדְרָשׁ"-בְּרָכוֹת כֹּחַ ע"א, וְכֵן:"חָנֵף- אֵין תּוֹכוֹ כְּבָרוֹ, אֲבָל לֹא יַעֲשֶׂה רַע בְּגָלוּי"- מַלְבִּי"ם בֵּאוּר הַמִּלּוֹת, יְשַׁעְיָהוּ י ו , וְכֵן:"יָצְאוּ הַשַּׁחְצָנִים, גַּסֵּי הָרוּחַ הַלָּלוּ, שֶׁאֵין תּוֹכָם כְּבָרָם וּמִתְנַהֲגִים בְּתַרְמִית וְעָרְמָה כְּדַרְכָּם"-מֶנְדֵּלֵי / בְּיָמִים הַהֵם, וְכֵן:"עֵינִי ח' יְהוּדָה,שֶׁנִּמְשָׁכוֹת תָּדִיר אַחֲרָיו,מִבְּחִינוֹת שֶׁאֵין תּוֹכוֹ כְּבָרוֹ"- י. בּוּרְלָא/ כִּסּוּפִים,155).