Genesis 16:15 simply states the following:
Hagar bore a son for Abram: Hagar, Sarai's servant, gave birth to a son whose father was Abram.
Abram called the name of his son, whom Hagar bore, Ishmael: Abram named the son Hagar bore him "Ishmael."
In the context of the broader narrative, this verse signifies the fulfillment of God's promise in Genesis 16:10 where the angel of the Lord told Hagar "I will so greatly multiply your offspring that they cannot be counted for multitude".
Genesis 16:15 simply states the following:
Hagar bore a son for Abram: Hagar, Sarai's servant, gave birth to a son whose father was Abram.
Abram called the name of his son, whom Hagar bore, Ishmael: Abram named the son Hagar bore him "Ishmael."
In the context of the broader narrative, this verse signifies the fulfillment of God's promise in Genesis 16:10 where the angel of the Lord told Hagar "I will so greatly multiply your offspring that they cannot be counted for multitude".