Yet, in the Kitāb-i Īqān (para. 203), he writes: 

[A] certain man, reputed for his learning and attainments, and accounting himself as one of the pre-eminent leaders of his people, hath in his book denounced and vilified all the exponents of true learning [...] We felt it necessary to refer to his books, in order that We might answer Our questioners with knowledge and understanding. His works, in the Arabic tongue, were, however, not available, until one day a certain man informed Us that one of his compositions, entitled Irshadu’l-‘Avám, could be found in this city [...] We sent for the book, and kept it with Us a few days. It was probably referred to twice.

http://bahaism.blogspot.com/