Letter 268 of Augustine was written at an unknown time during his episcopate. The bishop, presumably absent from Hippo at the time, writes to some important laymen of his Church ("dominis sanctae plebis cui ministro"), asking them to make a collection to repay the debt of seventeen solids that he incurred to pay the debts of a certain Fascius, who sought asylum in the church from his creditors.
Augustine claims that he has already written to the presbyters to cover the rest of the debt if the sum made by collection turns out to be insufficient.
The passage shows us that the presbyters controlled the treasury of the church of Hippo, at least during Augustine's absence (if he had been present at Hippo at the time, he rather would not have written to them). On the other hand, Augustine did not ask them to provide the money needed, but ordered it.