The subject is from a comedy by Antonio de Zamora. The timorous Don Claudio, the main protagonist of the play, replenishes with oil the lamp on which he has been led to believe his life depends. The inscription refers to his speech at this point in the play 'Lam[para] Desco[munal]', 'monstrous lamp'.
The composition may have been suggested to Goya by a stage presentation. The picture is one of six scenes of witchcraft etc. painted for the Duke of Osuna and paid for in 1798.
