Nabhan reports from Umm Salamah (may Allah be pleased with her) that he was with Lady Umm Salamah (may Allah be pleased with her), so she asked: "How much of your price for freedom remains?" Nabhan (may Allah be pleased with him) mentioned the amount, so Lady Umm Salamah (may Allah be pleased with her) ordered that "the amount be paid to my brother or nephew," and Lady Umm Salamah (may Allah be pleased with her) began to observe veiling from him and said: The Prophet (peace and blessings of Allah be upon him) said: "When any of you has a slave who is a mukatab (contracted to buy his freedom) and he possesses enough money to pay the price of his freedom, then she should observe veiling from that slave."
Hadith Referenceالسنن المأثورة / باب في أكل لحوم الخيل والبغال والحمير / 585
Hadith Takhrijسنن ابی داؤد العتق باب فی المکاتب یؤدی بعض کتائبہ الخ، رقم: 3928 وقال الالبانی: ضعیف، سنن ترمذی، البیوع، باب ماجاء فی المکاتب اذا کان عندہ ما یؤدی، رقم: 1261 وقال حسن صحیح۔