Sayyiduna Anas (may Allah be pleased with him) narrates: There were twenty young men of the Ansar who stayed with the Prophet (peace and blessings be upon him) to attend to his needs. When the Prophet (peace and blessings be upon him) intended to get something done, he would send them (or one of them) for that task.
Al-Bazzar recorded it; its chain contains narrators whom I do not know.