Darby's translation notes (1890)
Ephesians 4 - Introduction
1:1 at (a-19) Lit. 'in,' as Acts 13:1 ; Revelation 2:1 . Ephesus. (b-20) It may be interesting to mention that though 'at Ephesus' is found in almost all copies, many authorities would leave it out. Some, without sufficient ground, have considered it as a kind of circular. Compare Colossians 4:16 .