Sayyiduna Ibn Abbas (may Allah be pleased with them both), explaining this verse: "Say to those of the captives who are in your hands" [Surah al-Anfal: 70], recited until: "what was taken from you" [Surah al-Anfal: 70], and said: Sayyiduna Abbas (may Allah be pleased with him) used to say: By Allah, this verse was revealed about me, when I told the Messenger of Allah (peace and blessings be upon him) of my acceptance of Islam and asked him (peace and blessings be upon him) to count the twenty uqiyahs that he (peace and blessings be upon him) had found with me (towards my ransom), but he (peace and blessings be upon him) refused to count them. Then Allah gave me, in place of those twenty uqiyahs, twenty slaves, each of whom traded with my wealth; and besides that I hope for the forgiveness of Allah.
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 11350