Xenia, the Greek term for the Laws of Hospitality, The custom in classical Greece and other ancient cultures that, if a traveler comes to a strange town, he can ask for food, shelter, and gifts to help him on his journey. In Greek tradition, the host was considered responsible for his guest's comfort and safety, and a breach of those laws of hospitality was thought to anger Zeus, God of the gods.
In the Odyssey there are a few instances in which the law of Xenia is broken, quite a few of those belong in book nine of the Odyssey, in which Odysseus and his men are lured into a Cyclops’ cave in which the owner, Polypheus, is angered and doesn’t care about the law of Xenia.
One example in which Polyphemus breaks Xenia is, when
he fails in offering Odysseus a drink or some food instead he rudely frightens them and ask them impolitely who they are and what they were doing in his cave. Polyphemus violates the law again when he eats some of Odysseus men, Xenia prohibits the host to make their guest unhappy, much less eat them.
Although sometimes hosts disliked their guests and even disliked Xenia, they only followed it in fear of Zeus, Polyphemus son of Poseidon, believed that his father would protect him of Zeus and his wrath, so he broke the law once more by keeping Odysseus and his men inside his cave. He then even proclaimed that he wasn’t afraid of Zeus punishment for breaking Xenia relying on his father, Poseidon. When Odysseus asks for his gift for being the guest at the Cyclops’ house the Cyclops reacts in anger, a common rule of Xenia is to present their guest with a precious gift but in this case he laughs and eats a few more men. At last, Odysseus manages to escape captivity by stabbing the large eye of Polyphemus. The Cyclops infuriated brings a curse upon him; for Odysseus to never reach his land, for the last time violating Xenia by casting a spell on his guests.