You come at me with a sword, spear, and shield, but I come in the name of the Lord.
46 God will deliver you to my hand, I’ll kill you and cut off your head.
Then I'll give your carcass to the birds and beasts, so that the earth will know there's a God in Israel.
48-49 When Goliath came near, David slang a stone into Goliath's forehead, killing him instantly.
51 Then he took Goliath's sword and cut off his head.
52-54 When the Philistines saw that Goliath was dead, they all ran away. The Israelites chased after them, killing them along the way, while David brought Goliath's head to Jerusalem.
55 When David left to fight Goliath, Saul said to his captain, Abner, "Who is this young man?"
Abner said, "I don't know."
57 So when David returned after killing Goliath, Abner brought him to see Saul. (David was still carrying Goliath's head.)
He had a brass helmet, and a coat of mail that weighed 5000 shekels and spear head that weighed 600 shekels. (17:5-7)
Five thousand shekels, about one hundred and fifty lbs. (Oxford Annotated Bible note for v.5)
Six hundred shekels, about nineteen lbs. (Oxford Annotated Bible note for v.7)
Who is this young man? (17:55)
Saul doesn't recognize David even though the last chapter Saul is said to "love David greatly" and that David became his armor bearer. David even chased God's evil spirit away from Saul by playing his harp. (1 Samuel 16:21-23, Episode 108)