'Twelve' in the Bible

To you, my strength, I will sing praises. For God is my high tower, the God of my mercy. For the Chief Musician. To the tune of "The Lily of the Covenant." A teaching poem by David, when he fought with Aram Naharaim and with Aram Zobah, and Joab returned, and killed twelve thousand of Edom in the Valley of Salt.