The "its not personal its business" is really an urban legend that has grown up around The Godfather. The closest we come to it are the scenes where Tom tells Sonny that Sol's attempt on Vito wasn't personal, and Michael telling Sonny and everyone that his plan to kill Sol and McCluskey wasn't personal.
"Io sono stanco, sono imbigliato, and I wan't everyone here to know, there ain't gonna be no trouble from me..Don Corleone..Cicc' a port!"
"I stood in the courtroom like a fool."
"I am Constanza: Lord of the idiots."
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