Contradiction with 1 Corinthians 2:14
This verse states that spiritual things cannot be understood by the natural man, which contradicts Matthew 13:36 where Jesus explains the parable clearly to his disciples.
1 Corinthians 2:14: But the natural man receiveth not the things of the Spirit of God: for they are foolishness unto him: neither can he know [them], because they are spiritually discerned.
Contradiction with Matthew 13:11
Here, it's stated that the mysteries of the kingdom are given to the disciples to know, contrasting with 13:36 where they needed further explanation.
Matthew 13:11: He answered and said unto them, Because it is given unto you to know the mysteries of the kingdom of heaven, but to them it is not given.
Contradiction with Luke 8:10
Indicates that parables are meant to be mysteries, yet in Matthew 13:36, the mystery is explained.
Luke 8:10: And he said, Unto you it is given to know the mysteries of the kingdom of God: but to others in parables; that seeing they might not see, and hearing they might not understand.
Contradiction with Proverbs 25:2
Suggests that it's the glory of God to conceal a matter, whereas Matthew 13:36 involves revealing the meaning of a parable.
Proverbs 25:2: [It is] the glory of God to conceal a thing: but the honour of kings [is] to search out a matter.