Matthew 13:35
[This was] so that what was spoken by the prophet would be fulfilled, when he said [Psa. 78:2], "I will open my mouth [to speak] with parables. I will say things that have been hidden from the beginning of time."
Matthew 13:11-15
He replied, "You disciples are being given an understanding of the secrets of the kingdom of heaven, but the crowds of people are not.
Luke 12:3
Therefore, whatever you have said in the darkness [i.e., in obscurity] will be heard in the light [i.e., openly]. And what you have whispered in someone's ear in a back room, will be declared from the housetops.
2 Corinthians 3:12
Therefore, since we have such a hope [i.e., that the Gospel is much superior to the law], we speak with great boldness,