וְהָיָ֞ה אִם־לֹ֧א חָפַ֣צְתָּ בָּ֗הּ וְשִׁלַּחְתָּהּ֙ לְנַפְשָׁ֔הּ וּמָכֹ֥ר לֹא־תִמְכְּרֶ֖נָּה בַּכָּ֑סֶף לֹא־תִתְעַמֵּ֣ר בָּ֔הּ תַּ֖חַת אֲשֶׁ֥ר עִנִּיתָֽהּ׃ (ס)
And it shall be, if thou have no delight in her, then thou shalt let her go whither she will; but thou shalt not sell her at all for money, thou shalt not deal with her as a slave, because thou hast humbled her.
Shenei Luchot HaBerit
Commandment 533 prohibits the sale of such a prisoner of war once she has become the soldier's wife. The Torah (21,14) writes: "She must not be sold."