The list in Genesis 46:8–27 includes descendants who were likely not yet born when Jacob moved to Egypt. For example, Benjamin was twenty-three or twenty-four years old when the family moved to Egypt and thus was unlikely to have ten sons at that point (Genesis 46:21). Likewise, Perez was probably too young to be married with two sons (Genesis 46:12).1 Therefore, these descendants travelled to Egypt, not literally, but in the loins of their ancestors (Hebrews 7:10). This indicates that the number seventy has symbolic importance even though it refers to Jacob’s literal descendants.
The number seventy appears in several places in Scripture: the palm trees in Elim (Exodus 15:27), the elders of Israel (Exodus 24:1, Exodus 24:9; Numbers 11:16, Numbers 11:24–25), the sons of Gideon (Judges 8:30), those struck by the Lord in Beth-shemesh (1 Samuel 6:19), and the sons of Ahab (2 Kings 10:1), among others. Seventy is a multiple of seven, which denotes completeness, and is also an important number in ancient Ugaritic writings. With respect to Jacob’s descendants, the seventy nations of Genesis 10:1–32 are the likely background to Genesis 46:27 and Exodus 1:5.2,3 God had promised Abraham that through him all the families of the earth would be blessed (Genesis 12:3). Now, Abraham’s seed, the nation of Israel, is a microcosm of the seventy nations. Just as these nations spread over the earth after the flood (Genesis 10:32), so the seventy descendants of Jacob increase and fill the land of Egypt (Exodus 1:7).
5 All the descendants of Jacob were seventy persons; Joseph was already in Egypt.