Hebrews 11:12

Because of this faith of Abraham and Sarah, and the fruit of it in conceiving and bringing forth Isaac, was laid the foundation of a numerous seed by God's promise; from Abraham, a hundred, and Sarah, ninety years old, and barren, and both dead as to procreation, Romans 4:19, there were begotten a vast and unbounded seed, as the stars in the firmament, or the sand on the sea shore; and amongst them the teeming blessing, the one eminent Seed of Abraham, the Messiah, in whom all nations were to be blessed. Within four hundred years from the birth of Isaac, this seed increased to above six hundred thousand fighting men, besides women and children, and after increased to a stupendous greatness, according to the promise, Genesis 13:16, Genesis 15:5 Exodus 12:47 1 Chronicles 21:5,6.