'Twelve' in the Bible

And all the days of Seth were nine hundred and twelve years: and he died.

Twelve years they served Chedorlaomer, and in the thirteenth year they rebelled.

And as for Ishmael, I have heard thee: Behold, I have blessed him, and will make him fruitful, and will multiply him exceedingly; twelve princes shall he beget, and I will make him a great nation.

These are the sons of Ishmael, and these are their names, by their towns, and by their castles; twelve princes according to their nations.

And it came to pass, when Israel dwelt in that land, that Reuben went and lay with Bilhah his father's concubine: and Israel heard it. Now the sons of Jacob were twelve:

And the sons of Jacob are twelve. Sons of Leah: Jacob's first-born Reuben, and Simeon, and Levi, and Judah, and Issachar, and Zebulun.

And they said, Thy servants are twelve brethren, the sons of one man in the land of Canaan; and, behold, the youngest is this day with our father, and one is not.

We be twelve brethren, sons of our father; one is not, and the youngest is this day with our father in the land of Canaan.

All these are the twelve tribes of Israel: and this is it that their father spake unto them, and blessed them; every one according to his blessing he blessed them.