2 Samuel 2:11-15

And the time that David was king in Hebron over the house of Judah was seven years and six months.

And Abner the son of Ner, and the servants of Ish-bosheth the son of Saul, went out from Mahanaim to Gibeon.

And Joab the son of Zeruiah, and the servants of David, went out, and met together by the pool of Gibeon: and they sat down, the one on the one side of the pool, and the other on the other side of the pool.

And Abner said to Joab, Let the young men now arise, and play before us. And Joab said, Let them arise.

Then there arose and went over by number twelve of Benjamin, which pertained to Ish-bosheth the son of Saul, and twelve of the servants of David.