I thought I would weigh in on Matthew Henry. I'm probably a little unusual for a Biblehead in that I don't reject the use of his commentary by pastors. This goes along with my sense that God has always spoken truth through wise, godly individuals. Indeed, I would also be unpopular among many preaching professors to claim that the wisdom and God-given insight of the preacher has as much or more to do with the power of the sermon as the biblical text from which he or she preaches.
The reason I think this is because, in interpretation and in sermons, the communication is only as powerful as the reader or audience receive it. I can write something brilliant, but in the end it only ends up as brilliant as the reader can understand it. So the inspiration is only as effective as a person reading or hearing it can receive it. Apart from the Holy Spirit, the preacher is the most direct instrument of how a congregation receives the biblical text in a sermon.
So Matthew Henry was a wise man who had great spiritual insight. Why wouldn't a preacher draw from the well of the spiritual insights he had as he read the biblical texts?
1. So why do Bibleheads tend to discourage using him? Because he lived in the 1600 and 1700s. That directly implies at least three things. First, it means that he did not have the wealth of background information at his fingertips that you and I have today. He did not have the Dead Sea Scrolls. He did not have the Oxyrhynchus Papyri. He did not have the excavations of Jericho or Tel-Dan. No matter how smart or spiritual he was, he didn't have a massive amount of information that I can pull up on the internet here at Starbucks.
2. Secondly, he did not have the benefit of the interpretive discussion of the last 150 years. The commentaries get thicker and thicker. They go to two volumes and three volumes, as more people get PhDs in Bible. More people think up new educated possibilities given new evidence, given new discussions. That means someone like you or I can be further along than the greatest scholars of the last generation, because we not only have their brilliant thoughts but the brilliant thoughts of those who critiqued them.
I don't think most of us, including myself, have any real sense of how massive the gaps in our knowledge of the past are. This came home to me as I've done family research. The amount of good, educated guesses I've made that have been overturned by my oldest relatives makes me shudder to think of how wrong I must be about those who are dead.
And when you think of the Bible? We must be way off on the history time and time again. Indeed, I would strongly discourage using even the early church fathers if you are looking for historical insight on the biblical texts. The back and forth of scholars is helpful in this regard, even if much of it proves to be nonsense. Surely somewhere among all the whacky suggestions are the most likely ones, and surely the least likely ones are eliminated over time by this collective discussion.
3. Finally, and maybe most significantly, Matthew Henry lived before the historical revolution of the 1800s, when the world moved to a completely different level of understanding of what it means to interpret something in its historical context. Matthew Henry may be good at the literary context of the Bible, but he lived before the historical revolution. His interpretations of the Bible, like those of most Christians, including many evangelical scholars, are two-dimensional. As my colleague John Drury puts it, he was not yet "bit" by history (see Hans Frei). Reading in context is not merely knowing the dates and places, but knowing the deep cultural assumptions.
As John puts it, once you have been "bit" by history, you can't go back. You can achieve a "second naivete" in some area (Paul Ricoeur), but you can never really have that first naivete again. Once you understand what it means to read Leviticus against the deep, inexplicable category of purity in a primitive society, you can't ever read it again in terms of avoiding trichinosis in pork, I don't think.
So Matthew Henry is great for spiritual insight, but probably not the best source for what the text actually meant. The same would also go for Adam Clarke, in my opinion.