I should warn you before I post this line, that it gave me serious ear-worm once, for an extended period of time:
"de muchas tardes, para siempre juntas."
The last line of Jorge Guillén's poem "Los jardines" is "Sí, tu niñez, ya fibula de fuentes." Lorca took that line and used it as the beginning of another poem, which has nothing at all to do with Guillén. The line's meaning is completely altered by the new context.
I have the 1928 Cántico checked out of the library. It is the 1st edition and it is going to live with me in the office indefinitely, if I have to renew it 80 times. This should be in the rare book room, but my efforts have failed.