Answer:
This passage is an example of the epic convention of supernatural intervention or divine aid, where a character receives assistance from a supernatural or divine source. In this case, the character is offered a powerful drug that will protect him from the magic of Circe, the witch he is about to face. The source of the drug is not explicitly stated in this passage, but it is suggested that it has magical or divine properties that will counteract the effects of Circe's spells. The intervention of a divine or supernatural agent is a common feature of many epic poems, and is often used to heighten the drama and emphasize the importance of the events being described.