Umm Salama 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.” Tirmidhi, Abu Dawud and Ibn Majah transmitted it.

وَعَنْ أُمِّ سَلَمَةَ قَالَتْ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «إِذَا كَانَ عِنْدَ مكَاتب إحداكن وَفَاء فلنحتجب مِنْهُ» . رَوَاهُ التِّرْمِذِيُّ وَأَبُو دَاوُدَ وَابْنُ مَاجَهْ