Judges Chapter 4 tells how the Israelites again committed evil in God's sight after their judge Ehud was dead. So God sold them into the hand of King Jabin of Canaan, ruler in Hazor for 20 years. Jabin's army commander was Sisera and he assisted Jabin in cruelly oppressing Israel with 900 chariots of iron.
A prophetess named Deborah summoned a man named Barak and told him God was raising him up to be deliverer of His people. With armies drawn from the tribes of Naphtali and Zebulun, God promised Barak He would grant him victory over the forces of Commander Sisera. Barak said he would only go providing that Deborah would accompany him. She said she would, but because Barak did not have faith enough to obey God's orders and trust His promises without making this condition, he would not get full credit for the victory, for God would deliver Sisera into the hand of a woman.
And so it happened when the armies met that God helped Israel by making Sisera and all his soldiers fearful and panicky so that they could not defend themselves adequately. But while Israel was slaughtering their enemies, Sisera jumped down from his chariot and fled on foot to the tent of a woman named Jael who was the wife of Heber the Kenite. He assumed this would be a place of refuge for there were peaceful relations between King Jabin of Hazor and the clan of Heber the Kenite.
Jael met Sisera and welcomed him in, covering him with a rug. He asked for a drink of water but she opened a skin of milk and bundled him up to encourage sleep to his already weary body. He told her to guard the entrance and to say nobody was here if anyone came asking.
However when Barak came pursuing Sisera Jael led him in and showed him the man he was seeking. There before Barak's eyes lay Sisera dead. While he was asleep Jael had crept up to him with a hammer and tent peg in her hands and banged the peg right through his temples and into the ground pinning his body there. Talk about a splitting headache huh!