This chapter is full of symbolism that I only caught on the second read, and now I can't stop thinking about it.
The central symbol is cleanliness — or rather, the obsession with it. Shi Jinnian has a 'cleanliness obsession,' a psychological condition where he can't stand things he finds dirty. But what's fascinating is how this maps onto the emotional landscape of the story. Jiang Feng is 'dirty' — not just physically, but morally. He's vulgar, manipulative, and represents everything Shi Jinnian despises. Jiang Mian, on the other hand, is 'clean' in a completely different way. His innocence, his simplicity, his lack of guile — these are forms of purity that Shi Jinnian is drawn to.
The hand-washing scene is the most powerful symbol in the chapter. Jiang Mian washes his hands twice, disinfects them, because he wants to be acceptable to Shi Jinnian. He's performing cleanliness as an act of love, or at least as an act of survival. Meanwhile, Shi Jinnian can't accept the egg roll because he feels contaminated by Jiang Feng's touch — his cleanliness obsession becomes a barrier to intimacy.
Then there's the egg roll itself. Food as comfort, as connection, as the first taste of something good in a life that's been nothing but hardship. Jiang Mian sharing it with the ants — his 'good friends' — shows how he finds warmth in the smallest things. And the pink sweatshirt, the autumn sunlight, the lawn... these are all symbols of a world Jiang Mian has never experienced, a world of beauty and warmth that exists just beyond the basement.
The theme that ties it all together is belonging. Jiang Mian is constantly afraid of being kicked out, of not being clean enough, of not being worthy. But Shi Jinnian has never considered letting him go. The question the chapter asks is simple but devastating: who is actually dirty in this story?