1 Samuel 17:37-39 English Standard Version Anglicised (ESVUK)
37 And David said, “The Lord who delivered me from the paw of the lion and from the paw of the bear will deliver me from the hand of this Philistine.” And Saul said to David, “Go, and the Lord be with you!”
38 Then Saul clothed David with his armour. He put a helmet of bronze on his head and clothed him with a coat of mail, 39 and David strapped his sword over his armour. And he tried in vain to go, for he had not tested them. Then David said to Saul, “I cannot go with these, for I have not tested them.” So David put them off.