at the beginning of this chapter, the narrator states: "he grew rapidly like a yam tendril in the rainy season, and was full of sap of life." of whom is he speaking? what does this image indicate about this person?

This is from the novel "Things Fall Apart."

This quote is related to their adoptive son Ikemefuna. The boy had stayed with Okonkwo's family for three years. He grew big and strong. He was courageous and "masculine". Okonkwo approved of this and was happy that this "sap of life" was rubbing off on his natural son Nwoye.