A.T. Robertson Commentary Ephesians 3:5

"which in other generation was not made known unto the sons of men, as it hath now been revealed unto his holy apostles and prophets in the Spirit;" — Ephesians 3:5 (ASV)

In other generations (ετεραις γενεαις). Locative case of time. He had already claimed this revelation for himself (verse 3). Now he claims it for all the other apostles and prophets of God.