It is forbidden to speak rechiluth even if it is absolutely true, without admixture of falsehood, even if not before him [the object of the rechiluth], and even if he knows in himself that he would say it even to his face; and it is called "rechiluth." Much more so is it forbidden if he has the audacity to tell him to his face: You spoke or did this and this against him. His sin is far greater [if he tells him to his face]. First, for by telling him to his face he injects great hatred into the heart of the accused against him. For now it will be accepted by him as absolute truth in that he will say: "If it were not absolutely true, he would not dare speak thus to his face." And, furthermore, aside from this, he brings himself and these two to transgress through such rechiluth several explicit negative and positive commandments in the Torah (see the introduction, Negative Commandments, Principle XIV, and the note thereon).
אָסוּר לְסַפֵּר רְכִילוּת, אַף שֶׁהוּא אֱמֶת גָּמוּר, שֶׁאֵין בּוֹ שׁוּם תַּעֲרוֹבוֹת שֶׁקֶר, אֲפִלּוּ שֶׁלֹּא בְּפָנָיו, וַאֲפִלּוּ אִם הוּא יוֹדֵעַ בְּעַצְמוֹ, (א) שֶׁהָיָה אוֹמֵר דָּבָר זֶה אַף בְּפָנָיו, גַּם כֵּן אָסוּר, וּרְכִילוּת מִקְּרֵי. וְכָל שֶׁכֵּן אִם הוּא מֵעִיז פָּנָיו לוֹמַר לוֹ (ב) בְּפָנָיו מַמָּשׁ: אַתָּה דִּבַּרְתָּ עָלָיו, אוֹ עָשִׂיתָ לוֹ כָּךְ וְכָךְ, דְּאָסוּר, וַעֲוֹנוֹ גָּדוֹל הַרְבֵּה יוֹתֵר. אֶחָד, שֶׁבָּזֶה הוּא מַכְנִיס שִׂנְאָה חֲזָקָה בְּלִבּוֹ שֶׁל הַנִּדּוֹן עַל זֶה, כִּי מֵעַתָּה יִתְקַּבֵּל הַדָּבָר אֶצְלוֹ לֶאֱמֶת גָּמוּר, שֶׁבְּוַדַּאי יֹאמַר: אִלּוּלֵא שֶׁהַדָּבָר אֱמֶת גָּמוּר, לֹא הָיָה זֶה מֵעִיז פָּנָיו לוֹמַר לוֹ בְּפָנָיו מַמָּשׁ. וְעוֹד, לְבַד זֶה הוּא מַכְנִיס אֶת עַצְּמוֹ וְאֶת אֵלּוּ הַשְּׁנַיִם לַעֲבֹר עַל יְדֵי רְכִילוּת כָּזוֹ עַל כַּמָּה לָאוִין וַעֲשִׂין הַמְפֹרָשִׁין בַּתּוֹרָה, וְכַאֲשֶׁר בֵּאַרְתִּי כָּל זֶה הֵיטֵב בַּפְּתִיחָה בַּלָּאוִין אוֹת יד שָׁם בִּמְקוֹר הַחַיִּים בַּהַגָּהָה, עַיֵּן שָׁם.
It is forbidden to speak rechiluth even if it is absolutely true, without admixture of falsehood, even if not before him [the object of the rechiluth], and even if he knows in himself that he would say it even to his face; and it is called "rechiluth." Much more so is it forbidden if he has the audacity to tell him to his face: You spoke or did this and this against him. His sin is far greater [if he tells him to his face]. First, for by telling him to his face he injects great hatred into the heart of the accused against him. For now it will be accepted by him as absolute truth in that he will say: "If it were not absolutely true, he would not dare speak thus to his face." And, furthermore, aside from this, he brings himself and these two to transgress through such rechiluth several explicit negative and positive commandments in the Torah (see the introduction, Negative Commandments, Principle XIV, and the note thereon).