Summary — In this study the author attempts to find out the sources of Libro de los exenplos por ABC of Clement Sanchez, Archdeacon of Valderas. He demonstrates that at the very basis of this compilation there exist no classical original sources, but rather translated and collected works of which the most outstanding is the Sumtna de poenitenlii of the Franciscan Servasanto di Faenza- Sanchez places himself in a transition period that precedes humanism.