Keats admires the Nile throughout the sonnet. He calls it "fruitful" twice, which brings to mind the beautiful image of an abundance of growing food. He also states that it has been the "nurse" or caretaker of "swart" (which means darker-skinned) nations for thousands of years: "since the world began." He also pictures it as a seductive land where a person can rest. However, the most beautiful images of this river occur at the end of the poem. Here, the narrator, using apostrophe as he has throughout the sonnet to address the Nile, states that
Thou [you] dost bedew
Green rushes like our rivers, and dost taste
The pleasant sunrise. Green isles hast thou too,
And to the sea as happily dost haste.
Keats finds the Nile beautiful because he imagines it as similar to rivers in England. It "bedews," or moistens, "green rushes" growing near the water, just as English rivers do. It enjoys the "pleasant sunrise," as do English rivers. As the biggest rivers in England are dotted with "green isles," so is the Nile. Finally, like British rivers, the Nile rushes into the sea. Although the Nile is appreciated for the abundance it has afforded darker-skinned people, its main beauty, in the eyes of Keats's speaker, is in its similarity to England, which by implication has the most beautiful rivers of all.
Keats also renders the Nile beautiful and relatable by personifying it: it enjoys the sunrise as a human does, and the narrator pictures it "happily" hastening off to meet the sea.