Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) said concerning the saying of Allah Almighty, "And (also forbidden are) married women, except those whom your right hands possess" [Surah al-Nisa: 24], that there is no harm in having intercourse with slave-women after their wombs have been confirmed free of pregnancy (istibra'), even if they have husbands.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13956