It is narrated from Sayyiduna Sakhr bin al-Aylah (may Allah be pleased with him), who said: I took the paternal aunt of al-Mughirah bin Shu'bah (may Allah be pleased with him) captive and brought her to the Messenger of Allah (peace and blessings be upon him). Al-Mughirah (may Allah be pleased with him) came, and the Messenger of Allah (peace and blessings be upon him) asked about his aunt, and he said: "O Sakhr! When people accept Islam, they secure their wealth and their lives, so return her to them." So I handed her over to him. He said: The Prophet (peace and blessings be upon him) had given me some property of Banu Sulaym; then they accepted Islam and came to the Prophet (peace and blessings be upon him) and asked him for their property. The Prophet of Allah (peace and blessings be upon him) called me and said: "O Sakhr! When people accept Islam, they secure their wealth and their lives, so return it to them." So I returned it to them.
Hadith Referenceالمعجم الكبير للطبراني / باب الصاد / 7248