The Egyptians were accomplished astronomers, and certainly would know if the land was spinning out of the usual course. This being Velikovsky, he made use of this elsewhere.
There are several Biblical references that have a similar ring to them, too. It's plausible to theorize, as Velikovsky did, upon something extraterrestrial and large, that disturbed the normal course and rotation of the planet, passing in close enough proximity to rain down firey "hail" (brimstone?). Such a disruption would explain unusal storms and dramatic movements of the ocean as well.
full text available,
EARTH IN UPHEAVAL
http://www.archive.org/stream/earthupheaval010880mbp/earthupheaval010880mbp_djvu.txt