Why are the charges etc expected to be delivered verbatim by rote and not read out

The custom of delivering ritual orally from memory stems both from an ancient tradition of preserving esoteric instruction and from a deliberate method of mental and moral discipline 1.

Mackey identifies several primary reasons for maintaining an unwritten, oral delivery. First, committing instruction strictly to memory protects secret doctrines from the uninitiated and prevents their decay over time 1. Second, relying on oral transmission eliminates written texts that could otherwise spark endless verbal disputes, controversies, or schisms over personal interpretations 1. Third, increasing the difficulty required to acquire the material diminishes the likelihood of it being forgotten, using the memory as a secure casket for the principles received 1. Mackey compares this practice to similar traditions among the Druids, the Jewish oral law, the Cabala, and the early Christian Church, which all restricted sacred knowledge to verbal communication 1.

Before ritual books were printed, ceremonies were taught mouth-to-ear from master to apprentice, making memorization an essential aspect of self-improvement, discipline, and character-building aimed at improving concentration and developing the mind, as noted in an article on the United Grand Lodge of England's website. The same article observes that committing the ritual to memory was believed to ingrain its core moral lessons directly into a Mason's consciousness and way of thinking.