In Chapter 23, Holden has fun with Phoebe, they dance and sing. For the first time, he feels accepted and loved in the novel. This is symbolic of Holden's entire problem, he can't trust adults who are all phonies, he finds sincerity with his little sister.
It is only his little sister, Phoebe that Holden has a real connection with, someone who he communicates with in an honest way. At the heart of the book is Holden's desire to not grow up, in this chapter, he gets to be a little kid again, if only for a moment.
This chapter is symbolic of Holden's desire to remain a child, it is only as a child that he can be truly happy. It is also symbolic of the fact that Holden really does belong at home, he should not be running away from his family.
Holden and Phoebe are startled by the sound of the door to the apartment, their parents come home, and Holden hides in the closet. Phoebe has to lie to her mother, who smells cigarette smoke in her room because Holden was smoking, saying that she took only a few puffs.
At the end of the chapter, Holden needs money, Phoebe gives him her Christmas money and Holden is deeply touched by his sister's generosity, he cries. He gives her his red hunting hat in exchange.
Holden is comforted for the first time in the story, by his little sister, who loves him unconditionally.