It is narrated from Sayyiduna Makhlad al-Ghifari (may Allah be pleased with him) that three slaves of Banu Ghifar took part in the Battle of Badr with the Prophet (peace and blessings be upon him), and Sayyiduna Umar (may Allah be pleased with him) used to give each one of them a thousand.
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17978