2 Samuel 2:11-13 Revised Standard Version Catholic Edition (RSVCE)
11 And the time that David was king in Hebron over the house of Judah was seven years and six months.
The Battle of Gibeon
12 Abner the son of Ner, and the servants of Ish-bo′sheth the son of Saul, went out from Mahana′im to Gibeon. 13 And Jo′ab the son of Zeru′iah, and the servants of David, went out and met them at 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.