1 Samuel 17: 4: And there went out a champion out of the camp of the Philistines, named Goliath, of Gath, whose height was six cubits and a span.
2 Samuel 21: 15 – 22: Moreover the Philistines had yet war again with Israel; and David went down, and his servants with him, and fought against the Philistines: and David waxed faint. And Ishbibenob, which was of the sons of the giant, the weight of whose spear weighed three hundred shekels of brass in weight, he being girded with a new sword, thought to have slain David. But Abishai the son of Zeruiah succoured him, and smote the Philistine, and killed him. Then the men of David sware unto him, saying, Thou shalt go no more out with us to battle, that thou quench not the light of Israel. And it came to pass after this, that there was again a battle with the Philistines at Gob: then Sibbechai the Hushathite slew Saph, which was of the sons of the giant. And there was again a battle in Gob with the Philistines, where Elhanan the son of Jaareoregim, a Bethlehemite, slew the brother of Goliath the Gittite, the staff of whose spear was like a weaver’s beam. And there was yet a battle in Gath, where was a man of great stature, that had on every hand six fingers, and on every foot six toes, four and twenty in number; and he also was born to the giant. And when he defied Israel, Jonathan the son of Shimea the brother of David slew him. These four were born to the giant in Gath, and fell by the hand of David, and by the hand of his servants.
It is said that when David took five smooth stones from the brook (1 Samuel 17: 40) when he went out to meet Goliath, it was because Goliath had four brothers, and David intended to kill them as well. This is indeed interesting and plausible, for the brothers of Goliath would surely want to avenge his blood upon hearing that he had been killed.
The Bible tells us that the four giants mentioned in 2 Samuel 21 were sons of the giant in Gath. We must add Goliath of Gath with these four, because although he had already been killed by David in 1 Samuel 17, yet he is referenced as Goliath the Gittite in 2 Samuel 21; this is because a Gittite was an inhabitant of the Philistine city of Gath. Goliath’s four brothers are as follows: Lami (called “the brother of Goliath the Gittite” in 1 Chronicles 20: 5 and 2 Samuel 21: 19), Ishbibenob (2 Samuel 21: 16), Saph (2 Samuel 21: 18), and an unnamed brother with six fingers on each hand and six toes on each foot (2 Samuel 21: 20).