Ephesians 3:3-5

Amplified Bible

³ and that by [divine] revelation the mystery was made known to me, as I have already written in brief.^{(A) 4} By referring to this, when you read it you can understand my insight into the mystery of Christ, ⁵ which in other generations was not disclosed to mankind, as it has now been revealed to His holy apostles and prophets by the [Holy] Spirit;