What does Exodus 1:4 mean?

Four more of Jacob's sons are mentioned in this verse. Dan was the child of Jacob and Rachel's servant Bilhah. Rachel told Jacob to have a child with her so Rachel would have a child of her own since she was unable to have children at that time (Genesis 30:1–6). Jacob and Bilhah also had a second son named Naphtali, making Dan and Naphtali brothers with the same father and mother (Genesis 30:7–8).

Leah stopped bearing children for a time and she also gave Jacob her servant, named Zilpah, "as a wife" (Genesis 30:9). Jacob and Zilpah had two sons together named Gad and Asher, whose names mean "good fortune" and "happy" (Genesis 30:9–13). In their culture, sons born through a wife's servant were considered children of the servant's owner. Gad and Asher were both born in Paddan-aram (Genesis 35:26). Gad was one of the tribes to later receive an inheritance for his descendants east of the Jordan River (Joshua 18:7).