Equal to one thousand verses were revealed by Baha'u'llah within one hour.

"The revelations which came like a copious rain are unsurpassed in their beauty, richness and eloquence. The Holy Book of Qur'an consists of six thousand, three hundred verses revealed by Muhammad in twenty-three years. In this Dispensation, within one hour, equal to one thousand verses were revealed by Baha'u'llah, and as testified by Himself, were the secretary capable of recording, in a single day and night He could reveal equal to the Persian Bayan which the Bab revealed within one year, consisting of eight thousand verses."

https://bahai-library.com/wttp/PDF/A%20Glimpse%20of%20Glory.pdf