Goliath
Goliath is described in the biblical Book of Samuel as a Philistine giant defeated by the young David in single combat. The story signified Saul's unfitness to rule, as Saul himself should have fought for the Kingdom of Israel.
Biblical and Quranic narratives
In 2:246-248 of the Quran, God chooses Talut (generally considered to be Saul) to lead the Israelites into battle against the army of Goliath. On their way, God tells Talut to warn the men that they will be tested by God, and that they must not drink from the next river in order to pass the test. Despite this warning, most of the men disobey and drink from the river. God tells Talut to leave the disobedient members behind, unless they only drank one handful, so that the army will consist of only faithful members. The army then goes on to defeat General Goliath's army.