What does Genesis 21:19 mean?
Hagar and Ishmael were lost in the wilderness, out of water, and seemed likely to die. They were cast out of Abraham's family at the demand of Abraham's wife, Sarah (Genesis 21:9–10). Hagar had given up any hope of surviving, and walked some distance away from her son, so that she wouldn't have to watch him waste away (Genesis 21:15–16).Then, an angel of God called to Hagar from heaven. God had heard Ishmael's voice. The angel tells her not to give up yet. Ishmael will still become a great nation. This promise is the reason Abraham was willing—though heartbroken—to send them away (Genesis 21:11–13). Even when things look bleak, God's promises are still intact.
Here, God provides water. Just as He did when Hagar was pregnant (Genesis 16:7–13), the Lord demonstrates His intent to protect her son, Ishmael. Hagar suddenly sees a well she did not see before. She fills the skin Abraham gave to her, and she gives water to Ishmael.