William Burkitt on John 5:39

The next testimony which Christ appeals to, is the testimony of the scriptures; that is, the writings of Moses and the prophets, which Christ bids the Jews diligently search, and they shall find that they abundantly testified of him, and that all the prophecies and types were fulfilled in him. The word (search) signifying to search, as men do for a golden mine in the bowels of the earth, which they must dig deep for, before they can come at.

It intimates, 1. That there is an inestimable treasure lying hid in the holy scriptures, which we shall never fathom by a slight, superficial search.

2. That this inestimable treasure may be found out by the painful searcher: and it is the duty of all the members of the visible church to read and search the scriptures, which point out the way to eternal life.