Everything that Bahaullah is ever revealed, is a Part of the Book of God. In this instance, Bahaullah is referring to All His Revelation as 'Book'.Which book Bahaullah means here? Kindly give name of the book and the verse with the context verses. Please
For example Muhammad, during His mission, which was 23 years, revealed 114 Surrahs. Later, these Surrahs were put together as Chapters of One Book, which is called Quran.
Bahaullah's mission lasted 40 years, during which Bahaullah revealed more than 17000 Tablets. Even what you see commonly called Iqan, is a Tablet, that according to Bahai History, Bahaullah revealed it in 2 days only.
A Tablet means, a letter, which is written in response to questions of others...or as a Surrah, like chapters of Quran.
Bahaullah referred to All His Tablets and Works together, as One Book called Aqdas. This should not be confused by the Book of Law of Bahaullah, which is also called Aqdas. But, now, if Bahai's were to collect all 17000 works of Bahaullah into only One Book, it would be a huge Book with tens of thousands of pages. That is not practical, like Quran to put all of them in One Book. So, Bahais, instead, they made selections of His Tablets in different Books. For example 'Gleanings from the Writings of Bahaullah', is a collection of Tablets or Writings. However, some of the Tablets of Bahaullah, is like an independent Book. Those are kept as individual Books. For example Iqan is such a Book.