I wish that you had linked the comment or the context.

The problem is that the claim is not itself a very meaningful one, or rather it requires so much elaboration as to become problematic.

Problem 1: The Bible is not a single document, but a collection of documents that emerged in varying historical and chronological contexts over a period of hundreds of years. One does not 'verify' that kind of collection of documents. One verifies specific elements in specific documents by study of the historical contexts of their origins.

Problem 2: What does it mean to 'verify' something? Not all of the Biblical texts are presenting historical information. In this context verify probably means something like, "assess by external evidences whether events reported to have occurred in the Bible are likely to have occurred or not." The nature of the events the Bible records is that often there are no other evidences for them. In some cases this is because there is simply no other evidence dealing with the events in question. In others we are left wondering whether there were any events in question.

Problem 3: Plenty of things within the Biblical texts do 'match' with known evidences. I'm thinking of some of the socio-historical details found in the Acts narrative, in particular. On the other hand, for many things the Biblical texts are themselves the primary evidence at hand. For some things, the only evidence. In the latter case, verification is impossible.

Problem 4: Verifiability of other documents in comparison. Here's where the claim becomes truly problematic. We have, for instance, just ridiculous tonnes of documentary data for more recent history. Say 20th century history. Most of which is far more verified, simply because it's more verifiable. When you have a wealth of data, your ability to do historical work becomes greater, and generally you can have greater confidence in your reconstruction of events. We don't have this amount of data for Biblical periods, and we never will; this is why "most verified" is not really meaningful, unless you want to compare with analogous ancient documents.

Given the many supernatural incidents mentioned in The Bible, how can they be verified ? Really curious.

The comment talks about "verified" in the sense that lots of historical copies of the manuscript exist. NOT that the content of the Bible is verified.

It is true that the Bible is the ancient document where we have the largest number of preserved copies and fragments, and where the textual history is most thoroughly documented. Of course this is a wholly separate issue from how historical the events described in the text are.