Biblical References
Abraham's Seed as Sand on the Seashore.

Genesis 22

15: And the angel of the LORD called unto Abraham out of heaven the second time,

16: And said, By myself have I sworn, saith the LORD, for because thou hast done this thing, and hast not withheld thy son, thine only son:

17: That in blessing I will bless thee, and in multiplying I will multiply thy seed as the stars of the heaven, and as the sand which is upon the sea shore; and thy seed shall possess the gate of his enemies;

18: And in thy seed shall all the nations of the earth be blessed; because thou hast obeyed my voice.