The law of Moses pointed out the cases in which the servants of the Hebrews were to receive their freedom (Ex. 21:2-4, 7, 8; Lev. 25:39-42, 47-55; Deut. 15:12-18). Under the Roman law the "freeman" (ingenuus) was one born free; the "freedman" (libertinus) was a manumitted slave, and had not equal rights with the freeman (Acts 22:28; comp. Acts 16:37-39; 21:39; 22:25; 25:11, 12).
Easton's Bible Dictionary. M.G. Easton. 1897.