ENOfficial
Nafi' said he was informed by Safiya daughter of Abu ‘Ubaid that one of the Caliph’s slaves had intercourse with a girl who was among the fifth of the booty, forcing her to it against her will, and deflowered her. ‘Umar had him beaten but did not have her beaten because he had forced her against her will. Bukhari transmitted it.
Source: sunnah.com
Other translations
Arabic
عَنْ نَافِعٍ: أَنَّ صَفِيَّةَ بِنْتَ أَبِي عُبَيْدٍ أَخْبَرَتْهُ أَنَّ عَبْدًا مِنْ رَقِيقِ الْإِمَارَةِ وَقَعَ على وليدةٍ من الخُمسِ فاستَكرهَها حَتَّى افتضَّها فَجَلَدَهُ عُمَرُ وَلَمْ يَجْلِدْهَا مِنْ أَجْلِ أَنَّهُ استكرهها. رَوَاهُ البُخَارِيّ
sunnah.com