1 Samuel 7:3-10

And Samuel spake unto all the house of Israel, saying, If ye do return unto the LORD with all your hearts, then put away the strange gods and Ashtaroth from among you, and prepare your hearts unto the LORD, and serve him only: and he will deliver you out of the hand of the Philistines. Then the children of Israel did put away Baalim and Ashtaroth, and served the LORD only. And Samuel said, Gather all Israel to Mizpeh, and I will pray for you unto the LORD. And they gathered together to Mizpeh, and drew water, and poured it out before the LORD, and fasted on that day, and said there, We have sinned against the LORD. And Samuel judged the children of Israel in Mizpeh. And when the Philistines heard that the children of Israel were gathered together to Mizpeh, the lords of the Philistines went up against Israel. And when the children of Israel heard it, they were afraid of the Philistines. And the children of Israel said to Samuel, Cease not to cry unto the LORD our God for us, that he will save us out of the hand of the Philistines. And Samuel took a sucking lamb, and offered it for a burnt offering wholly unto the LORD: and Samuel cried unto the LORD for Israel; and the LORD heard him. And as Samuel was offering up the burnt offering, the Philistines drew near to battle against Israel: but the LORD thundered with a great thunder on that day upon the Philistines, and discomfited them; and they were smitten before Israel.