Sayyiduna Anas bin Malik (may Allah be pleased with him) said: Uthman (may Allah be pleased with him) set out as an emigrant to the land of Abyssinia, and with him was Ruqayyah, the daughter of the Messenger of Allah (peace and blessings be upon him). News of them failed to reach the Prophet (peace and blessings be upon him), and he (peace and blessings be upon him) would go out himself, waiting for news of them. Then a woman came and gave him news, and the Prophet (peace and blessings be upon him) said: "Uthman is the first person after Lut (peace be upon him) to emigrate to Allah with his family."
Hadith Referenceالمعجم الكبير للطبراني / العشرة / 142