in Christianity, a book containing portions of the Bible appointed to be read on particular days of the year. The word is also used for the list of such Scripture lessons. The early Christians adopted the Jewish custom of reading extracts from the Old Testament on the sabbath. They soon added extracts from the writings of the Apostles and Evangelists. During the 3rd and 4th centuries, several systems of lessons were devised for churches of various localities. One of the first attempts for a diocese to fix definite readings for special seasons during the year was made by Musaeus of Marseille in the mid-5th century.
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