A tautophrase is a phrase or sentence that repeats an idea in the same words. The name was coined by William Safire in The New York Times.
Examples include:
"A man's gotta do what a man's gotta do" (John Wayne)
"It ain't over 'till it's over" (Yogi Berra)
"What's done is done." (Shakespeare's Macbeth)
"I am that I am." (God, Exodus 3:14)
"Tomorrow is tomorrow" (Antigone (Sophocles))
"A rose is a rose is a rose." (Gertrude Stein)
"Sometimes a cigar is just a cigar." (Sigmund Freud)
"I yam what I yam and that's all that I yam!" (Popeye)
"Let bygones be bygones."
"Facts are facts."
"A deal is a deal is a deal."
"Once it's gone it's gone."
"It is what it is."
"Boys will be boys."
"A win is a win."
"You do you."
"A la guerre comme à la guerre" — A French phrase literally meaning "at war as at war", and figuratively roughly equivalent to the English phrase "All's fair in love and war"
Qué será, será or che será, será — grammatically incorrect English loan from the Italian, meaning "Whatever will be, will be."
"Call a spade a spade."