What is the significance of chapter eleven to the story?

The chapter begins with Ekwefi telling Ezinma the tale of the tortoise. This scene is significant because it illustrates the importance of oral tradition in Igbo culture and offers a telling proverb. The proverb is as follows: "A man who makes trouble for others is also making it for himself" (Achebe, 69). This proverb relates to Okonkwo and indicates that he will ultimately bring misfortune upon himself. When Ekwefi finishes the story, the priestess of Agbala, Chielo, visits Okonkwo's compound and takes Ezinma to Agbala's house in the sacred cave. Ekwefi worries about her daughter and follows Chielo through the dark, foreboding forest. After walking all night, Chielo takes Ezinma inside the cave and Ekwefi waits outside. Ekwefi then hears something behind her and turns around to see Okonkwo holding a machete. Okonkwo waits with his wife outside of the cave, and Ekwefi is comforted by his presence.
This particular chapter is significant because it depicts Ekwefi's courage and uncharacteristically portrays Okonkwo. Okonkwo is depicted as a concerned, sympathetic parent who puts his family above the cultural tradition. He is also portrayed as a supportive, caring husband, who comforts his wife by following her to Agbala's cave. Okonkwo's affinity for Ezinma is also evident in his decision to travel to the cave and keep watch outside. This is one of the rare scenes where Okonkwo's sensitive, compassionate nature is depicted, which enhances his seemingly static personality.