The ruler of the Copts sent the Messenger of Allah ﷺ a gift of two Coptic slave girls who were sisters, along with a mule. The Messenger of Allah ﷺ used to ride the mule, and he took one of the two girls as a concubine, and she bore him Ibrahim. As for the other, he gave her to Hassan bin Thabit al-Ansari.
أهدى أمير القبط لرسول الله ﷺ جاريتين أختين قبطيتين، وبغلة، فأما البغلة فكان رسول الله ﷺ يركبها، وأما إحدى الجاريتين فتسراها، فولدت له إبراهيم، وأما الأخرى فأعطاها حسان بن ثابت الأنصاري.
Harith bin Abu Usama narrated it in his Musnad (452 - Bughyat Bahith), and Tahawi in Sharh Mushkil (2569), and Tabarani in Al-Awsat (2059, Majma Bahrayn), through various routes from Hatim bin Ismail, from Bashir bin Muhajir, from Abdullah bin Burayda, from his father, and so on. The wording given here follows Tahawi's version. Its chain is hasan because of Bashir bin Muhajir, for his narrations are hasan so long as he does not report something objectionable. Busiri said in Al-Ithaf (3/43), "This is a sahih chain."Bazzar also narrated it (4423) from Muhammad bin Ziyad, from Ibn Uyayna, from Bashir bin Muhajir, with similar wording. He said, "Muhammad bin Ziyad made an error in this hadith when he attributed it to Ibn Uyayna, for Ibn Uyayna has no narration from Bashir bin Muhajir. Rather, this hadith was narrated from Bashir bin Muhajir by Hatim bin Ismail and Dalham bin Dahtham." End of quote.