The sentence "Rose is a rose is a rose is a rose."
was written by Gertrude Stein as part of the 1913 poem Sacred Emily,
which appeared in the 1922 book Geography and Plays.
In that poem, the first "Rose" is the name of a woman.
Stein later used variations on the phrase in other writings,
and "A rose is a rose is a rose" is probably her most famous quote,
often interpreted as "things are what they are".
In Stein's view, the sentence expresses
the fact that simply using the name of a thing already
invokes the imagery and emotions associated with it.