The Book of Hastings was one of the later books of the Holy Writ, dealing with the teachings of the Archangel Hastings, more precisely the shape and nature of Safeholds oceans and landmasses.

It was in fact an atlas of the planet, based on the maps Pei Shan-wei and her team made at the time of the original terraforming. The master maps from which all copies in the book were made were carefully hidden away in the Temple of God, as they were considered among the Church's most valuable artifacts. (OAR)

The original Book of Hastings was made of advanced synthetics which were fireproof, waterproof, and as tough as a five-millimeter sheet of hammered copper. Within the book, it stated that it was required that copies of its maps be made available to the public, as well as the Church, in the cathedral of every bishop.

The Book of Hastings also conclusively demonstrated that the world was a sphere, and explicitly taught Safeholdians the Ptolemaic theory of the universe. (OAR)

By ancient tradition, there was always a blank page between the first page of the Book of Hastings and the last page of the preceeding Book of Chihiro. (BSRA)