 The fasting of Jesus in the desert for forty days is used as a biblical justification of retreats.The retreat was popularised in Roman Catholicism by the Society of Jesus (Jesuits), whose founder, St. Ignatius of Loyola, as a layman began, in the 1520s, directing others in making (participating in) the exercises.Another form the Exercises came in, which became known as the nineteenth "Observation", 'allowed continuing one's ordinary occupations with the proviso of setting aside a few hours a day for this special purpose.'