There are two Goliaths mentioned in the bible. David slew one. David was just a lad when he slew this Goliath.
1Sa 17:4 And a champion went out from the camp of the Philistines, named Goliath, from Gath, whose height was six cubits and a span.
1Sa 17:23 Then as he talked with them, there was the champion, the Philistine of Gath, Goliath by name, coming up from the armies of the Philistines; and he spoke according to the same words. So David heard them.
1Sa 17:49 Then David put his hand in his bag and took out a stone; and he slung it and struck the Philistine in his forehead, so that the stone sank into his forehead, and he fell on his face to the earth.
‘The brother of’ has been added to this verse to try to make the bible correct. This should never be done, as there are many warnings about changing scripture. Elhanen killed this giant, whose name was also Goliath. David was getting on in years when Elhanan killed the second Goliath.
2Sa 21:19 Again there was war at Gob with the Philistines, where Elhanan the son of Jaare-Oregim the Bethlehemite killed the brother of Goliath the Gittite, the shaft of whose spear was like a weaver's beam.
Notice in this verse ‘the brother of’ is inspired. This is a different Elhanan.
1Ch 20:5 Again there was war with the Philistines, and Elhanan the son of Jair killed Lahmi the brother of Goliath the Gittite, the shaft of whose spear was like a weaver's beam.
David was a lad when he killed the first Goliath, who was a giant.
Elhanan, the son of Jaare-oregim killed the second Goliath, who was also a giant.
Elhanan, the son of Jair [this is a different Elhanan.] killed the second Goliath’s brother: Lahmi, also a giant.
Saul was alive when David slew Goliath.
1Sa 17:2 And Saul and the men of Israel were gathered together, and they encamped in the Valley of Elah, and drew up in battle array against the Philistines.
Saul was dead when Elanhan slew his goliath.
buried the bones of Saul and Jonathan his son in
the country of Benjamin in Zelah, in the tomb of
The bible is full of little posers like this.