The Tunnel by Ernesto Sábato:
‘There is nothing we can do. I cannot violate the regulation.’
‘A regulation, as I am sure you know, must be logical.’ I sputtered. On the woman’s cheek there was a mole punctuated with a few long hairs that was truly beginning to offend me.
‘And you know the regulation?’ she inquired scornfully.
‘It is not necessary to know the regulation, Señora,’ I replied icily, knowing that the word Señora would cut her to the quick.