“Amado mio
When we're together
I'm in a dream world
Of sweet delight.”

The Razor's Edge (1943)
Context: Nothing in the world is permanent, and we're foolish when we ask anything to last, but surely we're still more foolish not to take delight in it while we have it. If change is of the essence of existence one would have thought it only sensible to make it the premise of our philosophy.

Là corre il mondo, ove più versi
Di sue dolcezze il lusinghier Parnaso;
E che 'l vero condito in molli versi,
I più schivi allettando ha persuaso.
Canto I, stanza 3 (tr. Anthony Esolen)
Gerusalemme Liberata (1581)

Peace, p. 28.
The Unknown Eros and Other Poems (1877)

"Dream a Little Dream of Me" (1931), was one of Cass Elliot's biggest hits but the lyrics by Gus Kahn were written many years before her definitive rendition; the music by Fabian Andre & Wilbur Schwandt. More information on how she came to record it is provided at NPR: "Dream a Little Dream of Me" ranked as one of the 100 most important American musical works of the 20th century http://www.npr.org/programs/specials/vote/100list.html#D.
Misattributed

Source: Poems from the Pickering Manuscript (c. 1805), Auguries of Innocence, Line 123
Source: Songs of Experience

Ben Bolt, reported in Bartlett's Familiar Quotations, 10th ed. (1919).