God has spoken in his holiness:
(Psalm 60:6 ESV)
Faith is never happier than when it can fall back upon the promise of God. She sets this over against all discouraging circumstances; let outward providences say what they will, the voice of a faithful God drowns every sound of tear. God had promised Israel victory, and David the kingdom; the holiness of God secured the fulfilment of his own covenant, and therefore the king spake confidently. The goodly land had been secured to the tribes by the promise made to Abraham, and that divine grant was an abundantly sufficient warrant for the belief that Israel’s arms would be successful in battle. Believer make good use of this, and banish doubts while promises remain. I will rejoice, or “I will triumph.” Faith regards the promise not as fiction but fact, and therefore drinks in joy from it, and grasps victory by it. “God hath spoken; I will rejoice:” here is a fit motto for every soldier of the cross.