Genesis chapter 16 contains the events of the birth of Ishmael. Abram and Sarai still had not conceived a child, a decade had passed. Sarai suggests that Abram have a child with Sarai’s servant Hagar. When Hagar does get pregnant, Hagar despises Sarai and is treated harshly in return. So, Hagar runs away, but an angel of the Lord speaks to her and tells her to return and submit to Sarai. Hagar has a son and they name him Ishmael. This chapter shows that God’s plans are bigger than the plans of humans.
Since they still had no children, Sarai convinces Abram to have a child through Hagar. A son would be a legal heir according to the customs at that time.
After Hagar conceived, she treated Sarai disrespectfully. Sarai asks Abram to address the situation. Abram puts Hagar back under Sarai’s authority. She treats Hagar harshly and Hagar flees as a consequence.
As pregnant Hagar is running away, she meets the angel of the Lord. He tells her to return and submit to Sarai’s authority.
The angel of the Lord promised Hagar she will have numerous descendants. He tells her to name the baby “Ishmael” and that he will, unlike Hagar, be a free and independent man who will bow to no one.
Hagar recognized the angel to be God. She returned and bore a son to Abram. They named him Ishmael.