The word translated as "scriptures" has a non-religious meaning of "writings." It is always translated as "scripture" in the Bible, a religious word. This indicates that the only common writings in Jesus's society was his people's religious books.
The verb translated as "knowing/know" is the past perfect of "to see." In Greek, "having seen" something is what we know." The word translated as "power" is the source of our word "dynamic" and "dynamite."