No, it is used in the text of "Le Barbier de Seville", in the Act 1, Scene 3,Bartholo asked her"Quel papier tenez-vous la?", and she replying the qoute that I put in the original question..."Ce sont....."
I do not know the play but if you google it you will see that it is indeed used as an alternative title. In the play it says that it is a new comedy play. Perhaps a case of mise en abyme? Or a play of the era?
Actually, I believe it was the title of an opera that Beaumarchais based his play off of. Also, it was used several times within le Barbier de Seville, a sort of motif of the play. It's one specific song sung within the play- or, at least, part of it is sung within the play, in Act III scene 4. It's a song about two young lovers together, Lindor and an unnamed girl.