A combustor includes an end cap, a combustion chamber downstream from the end cap, and a plurality of tubes that extends through the end cap to provide fluid communication through the end cap to the combustion chamber. A casing surrounds the end cap, and a conduit extends from the casing to the end cap. A duct extends around the conduit and inside the end cap to provide fluid communication to the end cap. A method for supplying fuel to a combustor includes flowing a working fluid through a plurality of tubes that extends axially through an end cap, supplying a first fluid through a conduit into the end cap, and supplying a second fluid through a duct spiraling around the conduit into the end cap.