Abdullah bin Umar reported,

Umar had bound himself during the days of ignorance to spend a night, or a day, in retreat at the Kaaba. So he asked the Prophet ﷺ about it, and he said, "Keep the retreat and fast."While Umar was in retreat, the people suddenly began calling out the takbir. Umar asked, "What is this, Abdullah?"Abdullah replied, "The captives of Hawazin. The Prophet ﷺ has set them free."Umar said, "And that slave girl as well," and he sent her off along with them.

حدثنا عبد الله بن عمر بن محمد بن أبان بن صالح القرشي حدثنا عمرو بن محمد يعني العنقزي عن عبد الله بن بديل بإسناده نحوه قال فبينما هو معتكف إذ كبر الناس فقال ما هذا يا عبد الله قال سبي هوازن أعتقهم النبي ﷺ قال وتلك الجارية فأرسلها معهم