I Samuel 17:31-40 says that the son of Jesse did not want to wear the armor of the king, and went to get five stones from the river to kill a giant.
But why did the young pastor use 5 stones to slay a giant ? He had already killed a bear and a lion with his own hands.
David was from Judah. He was equipped with Benjamites technics experts in a sling and He didn´t need as many stones for a single giant:
15And the children of Benjamin were numbered at that time out of the cities twenty and six thousand men that drew sword, beside the inhabitants of Gibeah, which were numbered seven hundred chosen men.
16Among all this people there were seven hundred chosen men lefthanded; every one could sling stones at an hair breadth, and not miss. (Judge 20:15-16)
When reading 2 Samuel 21:15-22 and 1 Chronicles 20:1-8 we can tell you that Goliath had 4 brothers. (He was the fifth) Ishbi-Benob, Saph, Lahmi, and a “Huge man”. All of those giants were sons of the Giant Rapha in Gath.
Rapha (hebrew word for GIANT), 2 Samuel 21:22, lived in Gath e had 5 sons (1 Chronicles s 20:8): Goliath (1 Samuel 17:23), Ishbi-Benob (2 Samuel 21:16), Saph was named as Sippai in 1 Chronicles 20:4, and also as Saph (2 Samuel 21:1), Lahmi (1 Chronicles 20:5), and the “huge man”. He also was descended from Rapha and murdered by David´s soldiers in Gath. (2 Samuel 21:20, 1 Chronicles 20:6). This man was the ugliest one because he had 6 toes in each foot and 6 fingers in each hand.
According to the historical norms and rules of the civilizations in Israel, a law of war forced the champions of their respective nations to be present in the campaigns of conquest in neighboring territory.
It shows us that not only Goliath was present in the Philistine army militia over the Valley of Elah in those days fighting against their oponent Israel but also his four brothers.
Goliath was a giant uncircumcised. Goliath had four brothers and uncircumcised with him too.
It tells us that David was there to kill not only Goliath but Four more giant brothers as well.