ISLAMABAD, Pakistan — After his father died, Ahmad Saeed took over the office on the ground floor of the family’s storied bookstore here, Saeed Book Bank. Then the elderly men started visiting, seeking to settle old debts.

“They all apologized and said they had tried to see my father while he was alive but his office was always too crowded and they were embarrassed,” Mr. Saeed said.

Five times such men arrived, hat in hand, not just to pay their respects to the son and family, but also to say they wanted to pay for books they had shoplifted as children. Mr. Saeed said his father, Saeed Jan Qureshi, who died of heart failure in September, would have been amused: He had always regarded book theft by children as an investment in a future where people still read, and thus become his customers.

The man himself became an oracle to those looking for advice on books, taking time to establish a personal connection and to urge favorites on visitors. (That is another thing his son has inherited: He asked a visitor if he had read “Fallen Leaves,” the last book by the prolific American historian Will Durant, published in 2014, more than 30 years after his death.)