Odysseus attacked the cyclops, made him go blind and even prevented him from receiving help from other cyclopes. The Cyclops knows that he will probably not be able to take revenge on Odysseus in the condition he is in, so he decides to ask for divine interference, so he pleads with Poseidon to interfere with Odysseus's journey home.
The sentence "We are also told that it is on account of this happening that people who have loved each other very much sometimes quarrel and are no longer friends." best indicates the story's message or theme.
