Sayana was an Indian scholar and commentator who lived in the 14th century. While he made significant contributions to the fields of linguistics, grammar, and Vedic literature, there is no evidence to suggest that he had knowledge of the speed of light as calculated by modern methods.
The modern calculation of the speed of light is attributed to various scientists and experiments conducted in the 17th and 18th centuries, such as Ole Rømer's measurements of the speed of light in 1676 and subsequent work by other scientists like James Bradley and Albert A. Michelson. The widely accepted value of the speed of light in a vacuum, approximately 299,792,458 meters per second, was established through these scientific endeavors.
While ancient civilizations and scholars made impressive advancements in various fields, including mathematics, astronomy, and philosophy, there is no evidence to suggest that they possessed knowledge of the speed of light as calculated by modern scientific methods prior to the 17th century. It's important to critically examine claims of ancient knowledge and consider the historical and scientific context in which such claims are made.
If there are specific hymns or texts mentioned by Sayana that you would like to explore further, please provide more details, and I'll do my best to provide additional information.