Contradiction with Proverbs 25:2
Proverbs 25:2 states it is the glory of God to conceal a matter, contrasting with Luke 8:9, where understanding is sought.
Proverbs 25:2: [It is] the glory of God to conceal a thing: but the honour of kings [is] to search out a matter.
Contradiction with Isaiah 6:9-10
This passage indicates people's hearts are made dull, contradicting the inquiry for understanding in Luke 8:9.
Isaiah 6:9-10: And he said, Go, and tell this people, Hear ye indeed, but understand not; and see ye indeed, but perceive not. [indeed, but understand: or, without ceasing, etc: Heb. in hearing, etc]
Contradiction with Matthew 13:10-11
Here, Jesus explains why He speaks in parables, which could be seen as hindering understanding, as opposed to the disciples seeking clarity in Luke 8:9.
Matthew 13:10-11: And the disciples came, and said unto him, Why speakest thou unto them in parables?