E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Ca Ira (it will go).
Called emphatically Le Carillon National of the French Revolution (1790). It went to the tune of the Carillon National, which Marie Antoinette was for ever strumming on her harpsichord.
Ça Ira was the rallying cry borrowed by the Federalists from Dr. Franklin of America, who used to say, in reference to the American revolution, Ah! ah! ça ira, ça ira! (twill be sure to do). The refrain of the carillon is
Ha! ha! It will speed, it will speed, it will speed!