What does Genesis 21:14 mean?

The concept of "slavery" most often seen in the Bible is a type of servanthood very different from the lifelong, abusive slavery modern people associate with the term. The slavery practiced by Egypt, on the other hand, brought them condemnation and judgment (Exodus 1:8–11; Exodus 3:9–10). It was not uncommon in this era to give a slave his or her freedom. With that freedom, however, would come the understanding that any children born to the slave, by the slave owner, would lose any claim on future inheritance. This appears to have been Sarah's intent in demanding that Abraham cast out Hagar and his firstborn son Ishmael.

After being instructed by God to do so, Abraham now complies. At first glance, this feels cold and uncaring. At the same time, we need to remember that God has promised to prosper Ishmael (Genesis 21:13). So, Abraham gives Hagar bread and water and sends her off to wander in the wilderness. We're not told of any parting words or additional provisions. From Abraham's earlier reaction, we can only assume that it wounded him deeply to send them away in such a fashion.

It's helpful to understand that Ishmael was likely about 16 years old at this time. He had been born when Abraham was 86. Abraham was 100 when Isaac was born, and this takes place after Isaac was weaned, likely at the age of two or three. When the passage says that Abraham placed the skin of water on Hagar's shoulder, "along with the child," we should not read that he placed Ishmael on her shoulder.

Mother and son walked away together into the wilderness of Beersheba, which would be in the desert region of the Negev. We're told they wandered. They had nowhere to go.