Mishneh Torah — Positive Mitzvot מצוות עשה, Chapter 218
The full Hebrew text of Mishneh Torah, Positive Mitzvot, Chapter 218, with English translation by Maimonides (Rambam).
לישא אונס שנאמר: "ולו תהיה לאישה" (דברים כב,כט).
For a rapist to marry the woman he raped, as [Deuteronomy 22:29] states: "She shall become his wife."