"If she is displeasing in the eyes of her master" (Exodus 21:8): "displeasing" means only that she did not find favor before him. "Who has not designated her" refers to the master. "Then he shall let her be redeemed" refers to the father. He may not designate her for two men at once; he may not sell her on condition to designate her, the words of Rabbi Yose the Galilean. Rabbi Akiva says: he may sell her, and if he wishes to designate her, he designates her. "To a foreign people" is a warning to the court not to sell her to a gentile. "In his dealing treacherously with her": once he has betrayed her and treated her with contempt and did not deal with her according to the law of free daughters, he too is not permitted to keep her, the words of Rabbi Yonatan ben Avtulmus. And "treachery" means only deceit, as it is said, "Judah has dealt treacherously" (Malachi 2:11), and it says, "for they have dealt very treacherously with Me." Rabbi Yishmael says: Scripture speaks of the master, who acquired her in order to designate her and did not designate her; he too is not permitted to keep her. Rabbi Akiva says: "in his dealing treacherously with her" means once he has spread his garment over her [taken her as a wife].
The Master Who Broke Faith With His Maidservant
Yalkut Shimoni on Torah 320:4
אִם רָעָה בְּעֵינֵי אֲדֹנֶיהָ, אֵין רָעָה, אֶלָּא שֶׁלֹּא גָּמְלָה חֶסֶד לְפָנָיו, אֲשֶׁר לֹא יְעָדָהּ, אָדוֹן. וְהֶפְדָּהּ, אָב, לֹא יְיַעֵד לִשְׁנַיִם כְּאֶחָד, לֹא יִמְכֹּר עַל מְנַת לְיַעֵד, דִּבְרֵי רַבִּי יוֹסֵי הַגְּלִילִי. רַבִּי עֲקִיבָא אוֹמֵר, מוֹכֵר, וְאִם רָצָה לְיַעֵד מְיַעֵד. לְעַם נָכְרִי, הֲרֵי זֶה אַזְהָרָה לְבֵית דִּין שֶׁלֹּא יִמְכְּרֶנָּה לְגוֹי. בְּבִגְדוֹ בָהּ, מֵאַחַר שֶׁבָּגַד בָּהּ וְנָהַג בָּהּ בִּזָּיוֹן וְלֹא נָהַג בָּהּ כְּמִשְׁפַּט הַבָּנוֹת, אַף הוּא אֵינוֹ רַשַּׁאי לְקַיְּמָהּ, דִּבְרֵי רַבִּי יוֹנָתָן בֶּן אַבְטוּלְמוּס. וְאֵין בְּגִידָה אֶלָּא שִׁקּוּר, שֶׁנֶּאֱמַר, (מלאכי ב, יא) "בָּגְדָה יְהוּדָה", וְאוֹמֵר "כִּי בָגוֹד בָּגְדוּ בִּי". רַבִּי יִשְׁמָעֵאל אוֹמֵר, בָּאָדוֹן הַכָּתוּב מְדַבֵּר, שֶׁלְּקָחָה עַל מְנַת לְיַיעֵד וְלֹא יִיעֵד, אַף הוּא אֵינוֹ רַשַּׁאי לְקַיְּימָהּ. רַבִּי עֲקִיבָא אוֹמֵר, בְּבִגְדוֹ בָהּ. מֵאַחַר שֶׁפֵּירֵשׂ בִּגְדּוֹ עָלֶיהָ.