Explanation:
Calypso allows Odysseus to leave her island because Zeus, the king of gods, sends Hermes, his messenger, to deliver a message to Calypso. Zeus, recognizing Odysseus’ plight and understanding that it is time for him to return home to Ithaca and his wife Penelope, instructs Calypso to release him. Although Calypso has grown fond of Odysseus during his seven years of captivity on her island, she ultimately acquiesces to the will of Zeus and aids Odysseus in constructing a raft to leave her shores. Thus, the divine intervention and the adherence to Zeus’ commands are the primary reasons why Calypso allows Odysseus to depart from her enchanting island.