Commentary on the Apocalypse, on 12:1 — as quoted by Pitre (p 132); translation: as summarised by Pitre (endnotes), from John N. Suggit's translation (Fathers of the Church 112, 2006)
Oecumenius identifies 'the woman clothed with the sun' in Revelation 12 as 'the mother of our Savior' and declares that 'the vision describes her as being in heaven and not on earth, as pure in soul and body…'; he sees an allusion to Isaiah's prophecy of the painless birth and interprets Mary's labour as 'free of pain.'
No freely usable English translation of this passage is online, so the note keeps Pitre's quotation and links to the full text. Translation: as summarised by Pitre (endnotes), from John N. Suggit's translation (Fathers of the Church 112, 2006).
Why Pitre cites it
The oldest surviving commentary on Revelation identifies the woman clothed with the sun as 'the mother of our Savior,' in heaven, 'pure in soul and body,' and reads her labour as 'free of pain.'