Baha’u’llah in a Tablet had specifically referred to the one who would oppose His appointed Center of the Covenant

“Now Moses said that after Him should come Joshua. The Christ said, addressing Peter, 'Thou art the Rock, and I will build My temple upon this Rock.' Jesus spoke this to Peter by word of mouth. The Blessed Perfection did not appoint His successor by statement of tongue, but in the 'Book of Ahd' ('Book of the Covenant'), He wrote it with His own Hand, commanding therein that all the branches and relations should look toward the Center of the Covenant. Also, in the Kitáb-i-Aqdas, revealed thirty years before His Ascension, it is mentioned in two places. During these thirty years these commands of the Blessed Perfection were known and clearly understood by all. Again, in a Tablet He refers specifically to this, naming one who would violate His Commands. This Tablet was dictated by the Blessed Perfection and written at His Command by the hand of Muhammad-‘Alí. Muhammad-‘Alí has made many copies of it. Therefore, we cannot deny what it says. If it was not so, Muhammad-‘Alí would be able to deny. When he violated the Covenant, he went out from the shadow of the Blessed Perfection. Bahá‘u’lláh also said in this Tablet mentioned, that if for an instant this one should disobey His Commands, he would become a 'fallen branch.' He mentioned this expressly for Muhammad-‘Alí, knowing that he would disobey and deny. He left no possibility for anyone to disobey or misunderstand what He commanded. If it were not so, Muhammad-‘Alí could do many things that would injure. As it is, he has appropriated many papers and Tablets written by the Blessed Perfection. It is possible for these writings to be altered, as the meanings in Persian are greatly changed by a single dot here and there. Before His Ascension, the Blessed Perfection said to me, 'I have given You all the papers.' He put them in two satchels and sent them to Me. After His Ascension, Muhammad-‘Alí said, 'You had better give me the two satchels to take care of.' He took them away and never returned them. He thought the Center of the Covenant would be helpless without these papers. But he did not realize that My strength is the assistance of the Blessed Perfection. If all the world combined against Me, I would still possess this power, and all the world could not take it away from Me. I can fight with this weapon forever and will always be victorious. It is a sword which can never be dulled, a magazine that is always filled.” (‘Abdu’l-Baha, notes of a table talk given in 1905, recorded by Julia M. Grundy, ‘Ten Days In the Light of ‘Akka’, Baha’i Publishing Trust, Wilmette, Ill., 1979)