"The rules of xenia are all but absolute: hospitality must be offered and must be accepted, and once accepted a permanent tie is created.
The Homeric poems provide a detailed guide as to the proper treatment to be accorded to the xenos. When Nestor and Odysseus come to Phthia on their mission of assembling the Greek army to go to Troy (//. xi 765 ff.), they find Peleus sacrificing in the aule of his palace, and they stand quietly waiting in the prothyra. Achilles (the youngest person present) sees them and jumps to his feet; he takes them by the hand, tells them to be seated, and puts food and drink (xeinia) beside them, "as is the xenos' right". After the food and drink come the questions.
This, the proper behaviour, is supported by a counter-example:
In Od. i 103 ff. Athena, disguised as the Taphian xenos, Mentes, comes to Odysseus' palace: she too stands quietly waiting in the prothyra—and is ignored. The suitors are playing at pessoi, and drinking and eating; Telemachus is sitting among them lost in misery and thinking about his father's return. Suddenly he sees Athena, and goes straight to the prothyra to take her by the hand and escort her into the palace. On seeing her, he is angry that a xenos should stand so long at the doorway, and in receiving her as a xenos should be received, indicates the importance of conferring timē upon the new arrival (note the linen cloth placed on the chair, and the footstool), and of diplomacy (Athena is placed at a distance from the suitors to avoid further embarrassment)."