Odysseus expected the Phaecians to be generous and wanted to accept their offerings because the Phaecians were known as models of hospitality. Moreover, Odysseus believed that telling them an entertaining story would make the Phaecians help him.
In Odyssey, the Phaecians are a group of people who inhabit the island of Scheria, which is ruled by Alcinous and Arete. They are skilled with different activities in the ocean. For that reason, they assure Odysseus returns safely to Ithaca. However, they are punished by Poseidon for being hospitable and generous with Odysseus later in the story.
