Ben Jonson's "Song: To Celia" starts with a famous metaphor: love as wine. To this speaker, love isn't just deliciously intoxicating: it's the most glorious beverage imaginable. No literal wine can live up to a mere glance from his beloved Celia.
The poem's first two lines present an image of lovers' eyes meeting as a kind of toast: a ceremonial beginning to something wonderful. The speaker begs his Celia to "drink to him" with her eyes and vows that he'll "pledge" her with an identical glance. This image suggests not just that the pair are about to enjoy the wine of love together, but that they're making a kind of promise. A "pledge," after all, can be both a toast and a vow. The speaker isn't just saying that he longs for Celia to return his loving gaze. He's saying that, once she does, he'll swear himself to her forever.
He'll even go one further. If Celia will only "leave a kiss but in the cup," it'll satisfy him so completely that he'll have no need for literal wine anymore. This suggests that Celia's kiss has all the powers wine has, and more: it can quench the speaker's metaphorical thirst, it can satisfy his tastes, it can get him drunk. But the wine of Celia's kiss is better than any real wine could be.
Even in these first four lines, the reader gets the sense that this speaker is pretty drunk on his love for Celia already. But he's not sloppy or exuberant in his drunkenness: he's intensely, quietly committed. Listen to his assonance in these lines:
Drink to me only with thine eyes,
And I will pledge with mine;
Or leave a kiss but in the cup,
And I’ll not look for wine.
That insistently repeated long /i/ sound—which will appear all through this first stanza—makes the speaker sound completely focused, suggesting that his life centers on his singleminded desire for Celia's love.