Bright Star, would I were stedfast as thou art— (line 1)
When you say that you want to be like someone (or something) else, it's usually because you feel that the other person (or thing) has something that you lack, or that you don't have enough of. Thus, when the speaker says that he wants to be more like the Bright Star, and, specifically, that he wants to be "stedfast" as it is, that shows us that he feels that he doesn't have enough "stedfastness." Now, being "stedfast" could mean many things in the context of this poem (see our discussion of the "Speaker" for more details on this problem). But one thing it might mean is simple staying power: the star will last for all eternity, while the speaker, like all humans, is doomed to die. If so, then the first line would express a contrast between the star and the speaker based on their experience of time. To see if this is true or not, we'd better keep reading.
And watching, with eternal lids apart (line 3)
Well, the third line of the poem definitely seems to back up the idea that the speaker is mainly thinking about the star in terms of time. The clue to this is in the word "eternal." The word "eternal" has two main meanings – one is "outside of time," i.e., in some other universe where time doesn't exist. The second meaning of "eternal" is the more familiar one: "lasting forever." In the context of Keats's poem, it seems most easy to interpret the word following the second, more familiar meaning: the speaker is contrasting the star to himself because it will last forever, while he is doomed to die. That said, you could still make an argument for the other meaning, if Keats's speaker is trying to say that the star is "above it all." Based on the rest of the poem, which interpretation do you think is better?
The moving waters at their priestlike task Of pure ablution round earth's human shores (lines 5-6)
Now we get to see what the Bright Star is spending all eternity watching: the endless flow of waters around the shores of the earth, performing the task of "ablution" – i.e., "purification" or "washing clean." Now, we don't know about you, but this kind of sounds like the waves are washing humanity off the shores, as if humanity itself were a kind of pollution. That's interesting in itself, but things actually get even cooler (if kind of scarier). Did you know that the English word "tide" actually comes from the same word as "time"? In some old-fashioned English expressions, the word "tide" is actually used to mean "time" – like in the Christmas carol "Deck The Halls," when they talk about "the yuletide carol," the word "yuletide" actually just means "Yule-time" or "Christmas-time." Even when the word "tide" is used in its modern meaning of the rising and falling of the ocean because of the gravity of the moon, it is still often connected with the idea of "time," as in the old expression "time and tide wait for no man." What does this all have to do with these two lines from Keats's poem? Well, he certainly doesn't mention the word tide, but the image of "moving waters" along the "shores" of the world kind of makes you think of it anyway, right? If so, you could basically think of the "moving waters" as…not quite a metaphor, but at least something that makes you think about time. It's almost as if the act of "pure ablution," the washing-away of humanity, refers to the passage of time that destroys one human generation after another. (Sorry to be such a downer, but it's true.) Of course, because the speaker is a human, this image of time's destruction of humanity underlines the contrast between the speaker and the Bright Star. Not just underlines it, but highlights it, puts it in ALL-CAPS and boldface, and makes it 72-point font.