Mother Teresa once went to a cash-and-carry-in London. She filled a huge trolley with food for her hostel for homeless men in Waterloo. At the till she was told the total was more than £500. “It’s for the poor,” she said. “Very admirable,” said the store’s owner, repeating the total. “No, you don’t understand,” she said. “It’s for the poor.”

The shopkeeper told the nun that it was she who did not understand: she still had to pay. To the embarrassment of the English volunteer who had driven her to the shop, a standoff ensued, with the nun and the owner reiterating their positions over and over. Eventually the customer waiting behind with his own trolley told the shopkeeper: “It’s all right, I’ll pay for hers.” “See?” the wily nun said to the volunteer as they loaded his boot, “I told you God would provide.”