Jamieson, Fausset and Brown on Genesis 16:7

7. And the angel of the Lord found her by a fountain--This well, pointed out by tradition, lay on the side of the caravan road, in the midst of Shur, a sandy desert on the west of Arabia-Petræa, to the extent of a hundred fifty miles, between Palestine and Egypt. By taking that direction, she seems to have intended to return to her relatives in that country. Nothing but pride, passion, and sullen obstinacy, could have driven any solitary person to brave the dangers of such an inhospitable wild; and she would have died, had not the timely appearance and words of the angel recalled her to reflection and duty.