Mar Saba
In 1973 Morton Smith published a book on a previously unknown letter of Clement of Alexandria. He stated that, while cataloging documents at the ancient monastery of Mar Saba in the summer of 1958, he discovered the text of the letter handwritten into the endpapers of Isaac Vossius' 1646 printed edition of the works of Ignatius of Antioch. This letter is consequently referred to as the Mar Saba letter of Clement of Alexandria. Smith also published a second book for the popular audience in 1974.