What purpose does Mary serve for the narrator in Invisible Man

Mary, the mother figure as implied by her Biblical name, arrives to restore the narrator to life so that the robin can function in his reconstructed world. Mary is a big, strong woman and he is pliant in her hands. She leads him to the dark coolness of her house which contrasts greatly with the bright, white world of the hospital and the orange sun which makes him faint outside of the subway. She replenishes some of what has been picked off of him, giving him food and sleep.