Hisham bin Urwah narrates from his father that Abu Amr Dhakwan was the slave of Sayyidah Aishah (may Allah be pleased with her), and she freed him. He used to lead her in the night prayer in Ramadan and lead her in prayer while he was a slave.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 5122