There is a noticeable difference in David's writing from this point forward. David realizes God's will is going be accomplished. He can look forward to the day where he will pull out his favorite musical instrument and sing praises to God for the victory.
Practically for us, when we are in the middle of a difficult battle or situation, we too can look forward to a day where we can praise Him for the victory in our "battles". We must trust God for the outcome itself as well as when it may happen, because as a child of God we are not fighting for victory but from victory.
Although many casualties may occur in battle, in the end, God defeats evil and honors truth. We must remember to allow Him to lead us to victory in our life and thank Him for the outcome.
Historically, David still had more battles to fight in life, no matter what was this particular situation. Instead of just worrying about the next battle, David took some time every now and then to praise God for the victory he had just experienced.
Don't wait until the end of all of our "battles" to give God praise, or else we will never get around to it. We simply need to pause every now and then and remember the God who fights our battles is all powerful and all knowing. He desires to guide our lives and grant us the victories He has planned for us. We ought to praise Him in advance for the outcome He has planned.