Sayyiduna al-Daylami (may Allah be pleased with him) narrates: I came to the Prophet (peace and blessings be upon him) while I had two sisters as wives whom I had married in the Days of Ignorance, and he (peace and blessings be upon him) said: "When you return, divorce one of them."
Hadith Referenceالمعجم الكبير للطبراني / باب الفاء / 15935