The water soon turned brown with weeks of dirt and sweat. I held my breath and dunked my head under the water. I scrubbed my hair with soap and dunked again, over and over until my hair was free of blood and filth. I rubbed the soap on a rag and scrubbed my skin until it burned. When even the soles of my feet were clean, I dried myself by the kitchen fire. How is this bath like a rebirth for Mattie? Explain.