Cicero argues in the speech De Provinciis Consularibus, delivered to the Senate in 56 B.C., that Caesar ought not be recalled from his command of the two Gallic provinces (plus his new conquests). He argued that his enemies Piso and Gabinius ought be recalled instead. One of the arguments that Cicero used was the comparative employment of dispatches and their respective reception by the Senate. On one hand Piso was tardy in notifying the Senate with dispatches outlining his activities, and on the other, Gabinius had his letters subject to ‘novel dishonour’, meanwhile Caesar, by comparison, had been voted almost innumerable honours for his dispatches:
vos enim, ad quos litteras L. Piso de suis rebus non audet mittere, qui Gabini litteras insigni quadam nota atque ignominia nova condemnastis, C. Caesari supplicationes decrevistis numero ut nemini uno ex bello, honore ut omnino nemini (Cic. Prov. cons. X.25)
For you (the Senate), to whom Piso does not dare to send letters concerning his affairs, you who condemned the letters of Gabinius with a certain mark of infamy and novel dishonour; you voted supplications to Gaius Caesar, in number as no man from one war, honour as altogether no other.
An intertextual reference can be seen here with the language of Caesar himself in the B.G. 2.34.4, when Caesar says that ex litteris Caesaris – “from the letters of Caesar” – the Senate voted 15 days of supplications. Caesar then notes, in similar terms to Cicero, this is was an honour quod ante id tempus accidit nulli “which before that time fell on no-one.”
Although the question of which text references which will depend on the view you take on the order of composition of the texts (which depends mostly how you think that Caesar’s commentary on the Gallic War was assembled and published).