Where in The Pearl does Kino say he is a man and insane?

Kino says, "I am a man" and "I am a man" instead of, "I am a man" as a response to the doctor's refusal to treat his son, Coyotito, in Chapter 4 of The Pearl. This shows Kino's inner turmoil and desperation as he tries to save his son's life, leading him to feel both helpless and enraged at the injustice he faces.