5 The total number of people born to Jacob was seventy. Joseph was already in Egypt. 6 Then Joseph died, and all his brothers, and that whole generation. 7 But the Israelites were fruitful and prolific; they multiplied and grew exceedingly strong, so that the land was filled with them.
Matthew Henry's Commentary on Exodus 1:5-7
Commentary on Exodus 1:1-7
(Read Exodus 1:1-7)
During more than 200 years, while Abraham, Isaac, and Jacob lived at liberty, the Hebrews increased slowly; only about seventy persons went down into Egypt. There, in about the same number of years, though under cruel bondage, they became a large nation. This wonderful increase was according to the promise long before made unto the fathers. Though the performance of God's promises is sometimes slow, it is always sure.