Selections from Isaiah are read on these four Sundays, on Christmas Day, and on the four or five Sundays which usually follow Christmas before septuagesima.
"The Prayer Book Explained"
Percival Jackson
At septuagesima we are anticipating Lent and the Passion: Genesis therefore supplies the Lessons, followed by Exodus at Passion-tide, and the other books in regular course.
"The Prayer Book Explained"
Percival Jackson
It begins with septuagesima Sunday because the church services then begin to prepare the minds of the faithful for the services of Lent, which are themselves the preparation for Easter.
"Our Calendar"
George Nichols Packer