Selling a female slave does not lead to her divorce.

Narrated 'Aisha:

(the wife of the Prophet) Three traditions were established concerning situations in which Barra was involved: When she was manumitted, she was given the option to keep her husband or leave him;
Allah's Apostle ﷺ said, "The wala is for the one who manumits, Once Allah's Apostle entered the house while some meat was being cooked in a pot, but only bread and some soup of the house were placed before, him. He said, "Don't I see the pot containing meat?" They said, "Yes, but that meat was given to Barira in charity (by someone), and you do not eat what it given in charity."The Prophet ﷺ said "That meat is alms for her, but for us it is a present."

حَدَّثَنَا إِسْمَاعِيلُ بْنُ عَبْدِ اللَّهِ، قَالَ حَدَّثَنِي مَالِكٌ، عَنْ رَبِيعَةَ بْنِ أَبِي عَبْدِ الرَّحْمَنِ، عَنِ الْقَاسِمِ بْنِ مُحَمَّدٍ، عَنْ عَائِشَةَ ـ رضى الله عنها ـ زَوْجِ النَّبِيِّ ﷺ قَالَتْ كَانَ فِي بَرِيرَةَ ثَلاَثُ سُنَنٍ، إِحْدَى السُّنَنِ أَنَّهَا أُعْتِقَتْ، فَخُيِّرَتْ فِي زَوْجِهَا. وَقَالَ رَسُولُ اللَّهِ ﷺ " الْوَلاَءُ لِمَنْ أَعْتَقَ ". وَدَخَلَ رَسُولُ اللَّهِ ﷺ وَالْبُرْمَةُ تَفُورُ بِلَحْمٍ، فَقُرِّبَ إِلَيْهِ خُبْزٌ وَأُدْمٌ مِنْ أُدْمِ الْبَيْتِ فَقَالَ " أَلَمْ أَرَ الْبُرْمَةَ فِيهَا لَحْمٌ ". قَالُوا بَلَى، وَلَكِنْ ذَلِكَ لَحْمٌ تُصُدِّقَ بِهِ عَلَى بَرِيرَةَ، وَأَنْتَ لاَ تَأْكُلُ الصَّدَقَةَ. قَالَ " عَلَيْهَا صَدَقَةٌ، وَلَنَا هَدِيَّةٌ ".