وَعَنْ أُمِّ سَلَمَةَ
قَالَتْ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «إِذَا كَانَ عِنْدَ مكَاتب إحداكن وَفَاء فلنحتجب مِنْهُ»
Umm Salamah reported God’s Messenger as spying, “When a slave of one of you women has made an agreement to purchase his freedom and can pay the full price, she must veil herself from him.”
Mishkat al-Masabih 3267, Book 15, Emancipation, Hadith 19. 1 min read