Read the post and you will find out what it is east of.Righteous man from the East - East of what? No exact co-ordinates. East of Iran? East of India? Thailand? China? Japan? Philippines? East Timor? Paris is East of London and Moscow is North-east of Paris.
That is true, but when you put all the pieces of the puzzle together, they all point to one man.You can make whatever you want of Isiah 41.2.
Even if there was no other proof of Baha'u'llah, the Bible prophecies would suffice as proof.