In On Heroes, Hero-Worship, and the Heroic in History (1841), Carlyle wrote:

“A wearisome confused jumble, crude, incondite… yet a wearisome confused jumble only to the careless reader. To a serious reader, it is another matter.”

Context: Although Carlyle acknowledged that the Qur’an can be difficult for first-time readers, he argued that sincere study reveals its profound power and authenticity.