By this I know that thou favourest me, because mine enemy doth not triumph over me.
Confident anticipation of his prayer being heard, since the cause and honour of God are at stake in his person.
By this I know that thou favourest me, because mine enemy doth not triumph over me - literally, 'doth not shout in triumph over me.' By faith he treats the internal assurance of deliverance as if it were an already-accomplished fact, and as the token whereby he knows God's favour toward him.