Vespers
so called from Vesper, the evening star, was also called hora lucerna ("lamp hour"). Originally, like that of all the canonical hours, of which at first it was the last, the service consisted of the singing of three psalms intermixed with some prayers.
According to the account of all the serv ices given in the Apostolic Constitutions, that for vespers opened with the 140th (141st) Psalm, which was followed by a prayer. A collect was next said by the bishop, and a benediction pronounced on the people, who were then dismissed. But different churches had different usages, and in some lessons were read, hymns sung, and other prayers offered.