Now Sarai Abram's wife bare him no children (literally, bare not to him, notwithstanding the promise; the barrenness of Sarai being introduced as the point of departure for the ensuing narrative, and emphasized as the cause or occasion of the subsequent transaction): and she had—literally, to her (there was)—an handmaid, an Egyptian (obtained probably while in the house of Pharaoh (Genesis 12:16)—whose name was Hagar—"flight," from hagar, to flee.
Cf. Hegirah, the flight of Mahomet. Not her original designation, but given to her afterwards, either because of her flight from Egypt (Ambrose, Wordsworth), or because of her escape from her mistress (Michaelis, Bush, 'Speaker's Commentary').
Though not the imaginary or mythical (Bohlen), it is doubtful if she was the real (Ainsworth, Bush), ancestor of the Hagarenes (1 Chronicles 5:10, 1 Chronicles 5:19, 1 Chronicles 5:20; 1 Chronicles 27:31; Psalms 83:6, Psalms 83:8).