[IDEM libro uicensimo sexto ad edictum. ] §2.14.51.prSi cum te ex causa legati debere pacisci debitori tuo existimas, pactus sit ne ab eo peteres: neque iure ipso liberatur debitor neque petentem summouebit exceptione conuentionis, ut Celsus libro uicensimo scribit.
[THE SAME, On the Edict, book 26] If, when you believe that you owe a debt to your debtor on account of a legacy, you have agreed not to sue him: the debtor is neither released ipso iure, nor will he bar the plaintiff by the exception of agreement, as Celsus writes in his twentieth book.
§2.14.51.1Idem eodem loco scribit, si debitorem tuum iussisti soluere Titio, cui legatum falso debere existimas, et debitor pactus sit cum Titio suo debitore constituto: neque tibi aduersus tuum debitorem neque ipsi aduersus suum actionem peremptam.
The same author writes in the same place that if you have ordered your debtor to pay Titius, to whom you falsely believe you owe a legacy, and the debtor has made an agreement with Titius, who was established as his creditor: neither is your action against your debtor extinguished, nor is his action against his own.