Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) narrates from Sayyiduna Bilal (may Allah be pleased with him); Bilal (may Allah be pleased with him) said: "The Prophet (peace and blessings be upon him) had a slave boy whose name was Rabah."
Hadith Referenceالمعجم الكبير للطبراني / باب الباء / 1055