The Messenger of Allah ﷺ said, "If the slave any of you has contracted to free has enough to pay off his contract, she should observe veiling from him."
حدثنا سعيد بن عبد الرحمن قال حدثنا سفيان بن عيينة عن الزهري عن نبهان مولى أم سلمة
قال رسول الله ﷺ إذا كان عند مكاتب إحداكن ما يؤدي فلتحتجب منه
[Its chain of transmission is hasan]. Abu Dawud narrated it, no. 3928 (see the previous hadith), and Ibn Majah narrated it, no. 2520, from the hadith of Sufyan bin Uyayna with the same wording. Ibn Hibban graded it sahih, no. 1214, as did Hakim, 2/219, and Dhahabi agreed with him. Zuhri stated clearly that he heard it directly, and Nabhan is hasan al-hadith. Dhahabi confirmed his reliability in Kashif, as did Tirmidhi, Ibn Hibban, and others.