Among other gifts, Odysseus had received some "ruddy, irresistible wine" from Maron, "a priest of Apollo," because Odysseus "rescued him, his wife and children, reverent as [Odysseus and his crew] were [...]." In other words, in their siege on Ismarus or in the battle which followed the next morning, they saved Maron out of respect for the office the man performs for the gods. Because he is a priest of Apollo, and because Odysseus and his men revere the gods, they save Maron's life and family and leave them in peace. Odysseus tells King Alcinous of Phaeacia, that "Whenever [Maron's guests would] drink the deep-red mellow vintage, twenty cups of water he’d stir in one of wine." Wine then was much thicker and very much more potent than wine is now; it was customary to dilute the wine with water to make it an appropriate drink. Odysseus takes a skin of this very strong wine, undiluted, into the Cyclops' cave, and it is this undiluted and excellent wine with which he gets Polyphemus drunk.
When Polyphemus eats Odysseus's men instead of welcoming them and treating them with hospitality, he disobeys the religious imperative to offer what the Greeks called "xenia". Xenia referred to the reciprocal relationship between host and guest: the host must offer whatever he can to welcome a guest—even including giving him a gift—and the guest must not take advantage of the host's generosity, and because Zeus protected travelers, offering xenia was not really optional if one wanted to stay on Zeus's good side. Polyphemus says to Odysseus, "'We Cyclops never blink at Zeus and Zeus’s shield of storm and thunder, or any other blessed god—we’ve got more force by far. I’d never spare you in fear of Zeus’s hatred, you or your comrades here, unless I had the urge.'" In other words, then, Polyphemus brags that he is stronger than Zeus and so he does not have to obey Zeus's laws. This does not go well for him.