Joshua 7:3 (KJV)

But the children of Israel committed a trespass in the accursed thing: for Achan, the son of Carmi, the son of Zabdi, the son of Zerah, of the tribe of Judah, took of the accursed thing: and the anger of the Lord was kindled against the children of Israel.

And Joshua sent men from Jericho to Ai, which is beside Beth–aven, on the east side of Beth–el, and spake unto them, saying, Go up and view the country. And the men went up and viewed Ai.

And they returned to Joshua, and said unto him, Let not all the people go up; but let about two or three thousand men go up and smite Ai; and make not all the people to labour thither; for they are but few.

So there went up thither of the people about three thousand men: and they fled before the men of Ai.

And the men of Ai smote of them about thirty and six men: for they chased them from before the gate even unto Shebarim, and smote them in the going down: wherefore the hearts of the people melted, and became as water.