Mark borrowed these two points and a lot of the structure of this sermon from Don Carson's very helpful sermon here.
- Jesus tells parables because in line with Scripture (Isaiah 6), His message blinds, deafens, and hardens (v 10-17)
- Jesus tells parables because in line with Scripture (Psalm 78), His message reveals things previously hidden in Scripture (v 34-35, 11-12, 16-17, 51-52)
You can watch this message here.