'Twelve' in the Bible

So they got up and went over by number: twelve for Benjamin and Ish-bosheth and twelve of the servants of David.

And when the children of Ammon saw that they had made themselves hated by David, they sent to the Aramaeans of Beth-rehob and Zobah, and got for payment twenty thousand footmen, and they got from the king of Maacah a thousand men, and from Tob twelve thousand.

Then Ahithophel said to Absalom, Let me take out twelve thousand men and this very night I will go after David: