The angel of the LORD found [Hagar] by a spring of water in the wilderness, the spring on the way to Shur. (Gen 16:7)
Sarai gave her slave Hagar to Abram so she could bear him a son. As disturbing as this sounds to us, it was an accepted practice in the patriarchal world. According to a legal contract unearthed at Nuzi in Mesopotamia,
If Gilimninu [the wife] bears children, Shennima [her husband] shall not take another wife. But if Gilimninu fails to bear children, Gilimninu shall get for Shennima a woman. In that case, Gilimninu shall have authority over the offspring. (E. A. Speiser, Genesis [Doubleday, 1964] 120)
Similarly, the law code of Hammurabi stipulates:
A priestess of the naditum rank‚ gives her husband a slave girl in order to provide him with a son. If the concubine then tries to arrogate to herself a position of equality with her mistress, the wife shall demote her to her former status of slave; but she may not sell her to others. (Speiser, 120)
Like many of the matriarchs of the book of Genesis, Hagar was a victim of circumstances beyond her control. Even by the standards of her times, she got a raw deal.
The Hebrew word for concubine is pileges, but a wife is an ‘ishshah. The two words describe two distinct arrangements between a man and a woman; they are not interchangeable. In Genesis, however, Hagar is called both a pileges and an ‘ishshah. (The same is true for Keturah, who bore six sons to Abraham [Gen 25:1, 6].) For example, Hagar is called Abram’s ‘ishshah in Genesis 16:3, but his pileges in Genesis 25:6. Unlike the rest of the Old Testament, where women are either wives or concubines, Hagar was somehow both.
Hagar’s role in this arrangement was not strictly to gratify Abram’s sexual appetites but to provide him an heir—a wifely “duty.” Within the limitations of the fallen culture of that day, such a role demanded a degree of respect: certainly more respect than she received. She was supposed to have been treated more like a wife and less like a sex slave.
Even so, God took note of her and appeared to her when it seemed she had no hope.