What does 1 Samuel 17:46 mean?

'Today the Lord will hand you over to me. I’ll strike you down and cut off your head. I’ll give the bodies of the Philistine army to the birds and wild animals today. Then everyone will know there’s a God in Israel.' 1 Samuel 17:46 - Modern Text Bible

(David boldly predicts victory, not just for himself but for God’s reputation.)