[GAIUS libro nono ad edictum prouinciale. ] §16.2.5.prSi quid a fideiussore petetur, aequissimum est eligere fideiussorem, quod ipsi an quod reo debetur, compensare malit: sed et si utrumque uelit compensare, audiendus est.
[GAIUS, On the Provincial Edict, Book IX.] If anything is demanded from a surety, it is most equitable that the surety should choose whether he prefers to set off what is owed to himself or what is owed to the principal debtor; but even if he wishes to set off both, he must be heard.