In the world of the Odyssey, you don’t know who’s at your door. The traveller arriving wet and hungry might be a beggar, a king in disguise, or a god testing your house. Xenia is the answer the Greek world settled on: treat every stranger as if they’re all three.
The bond is two-sided. The host offers a bath, a meal, a bed, and a safe night before asking the guest’s name. The guest receives the welcome without abusing it, accepts a parting gift, and reciprocates if the host ever knocks at their door. Zeus himself enforces the contract — to break xenia is to invoke his anger.
The whole plot of the Odyssey turns on xenia. Odysseus is rewarded by hosts who honour it (Nestor, Menelaus, Alkinoös) and devoured by hosts who don’t (Polyphemus). Meanwhile, back in Ithaca, the suitors are inverting xenia in his own house — eating his food, drinking his wine, hounding his wife — and that desecration is what makes their massacre, when it comes, righteous in Homer’s frame.
For us, xenia asks: how do you treat the unknown person who needs something from you? Before you know whether they’re “deserving”?