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.
7. children of Israel were fruitful—They were living in a land where, according to the testimony of an ancient author, mothers produced three and four sometimes at a birth; and a modern writer declares "the females in Egypt, as well among the human race as among animals, surpass all others in fruitfulness." To this natural circumstance must be added the fulfilment of the promise made to Abraham.