"This is the account of the family line of Abraham's son Ishmael, whom Sarah's slave, Hagar the Egyptian, bore to Abraham. These are the names of the sons of Ishmael, listed in the order of their birth: Nabaioth the firstborn of Ishmael, Kedar, Adbeel, Mibsam, Mishma, Dumah, Massa, Hadad, Tema, Jetur, Naphish and Kedemah. These were the sons of Ishmael, and these are the names of the twelve tribal rulers according to their settlements and camps." NIV translation
In this family line, we see that God kept His promise to Hagar and to Abraham. In chapter 16, God had promised Hagar that He would make her descendants numerous and, in chapter 17, God promised Abraham that twelve rulers would come from Ishmael.