"I will free you on the condition that you serve the Messenger of Allah ﷺ for as long as you live."I replied, "Even if you had not made that condition, I would never have parted from the Messenger of Allah ﷺ as long as I live."So she freed me and stipulated that condition upon me.
حدثنا مسدد بن مسرهد حدثنا عبد الوارث عن سعيد بن جمهان عن سفينة قال كنت مملوكا
أعتقك وأشترط عليك أن تخدم رسول الله ﷺ ما عشت فقلت وإن لم تشترطي علي ما فارقت رسول الله ﷺ ما عشت فأعتقتني واشترطت علي
No references are available.
[Its chain is hasan] Ibn Majah narrated it in the chapters on manumission, chapter on one who frees a slave and stipulates his service, no. 2526, from the hadith of Saeed bin Jumhan, and Ibn Jarud graded it sahih, no. 976, as did Hakim, 2/213–214, and Dhahabi agreed with him.