1. I don't think this is enough to state that the source is God ,in some situations extraordinary hidden human powers are revealed when external dispersions are eliminated or don't exist , this is a common practice practiced in many ways in religions like fasting ,and some types of meditations , and even self punishments and deprivation
2. How ?
We should consider at least all those 4 points at the same time in my previous post.
Baha'u'llah in 40 years prison and excile produced 17000 works scriptures, and these are available. When He wrote these, according to many witnesses, He didn't have to stop and think to write them. He was just saying these words once, without having to go back several times to correct His writings. In fact 40 years is about 14600 days, which means He produced at least one work per day. the fact that He didn't study religion or science makes this a mystery and a phenomina in my openion.
The fact that Baha'i Faith has many enemies, which for many years tried to find mistakes to repudiate theses scriptures, but they have failed to do so, is extraordinary, for the fact that these writings were written fast without spending too much time to eddit or correct or make the changes that the regular writers of Books normally do only to produce one work.
Also, He knew the verses of other older scriptures, such as Bible and Quran in His memory, and quoted many of these, and explained mystries in them, with no record of History that He studied these scriptures.
Also, He was in Iran, a country with Moslem majority, who believe in finality of revelation ofIslam, and yet, When the Bab and Baha'u'llah appeared and claimed a new revelation, in the short space of a few years, they had so many believers, who just 20,000 of them were killed by the Iranian government to stop the new faith, which they failed. This is why they killed the Bab and exciled Baha'u'llah from Iran to other counries and imprisoned Him for 40 years. There is a 400 page history about Baha' faith with many extraordinary events too.