How amusing that you demand unmistakable proof, yet you yourself never offer any that is of merit!
I know you directed this challenge to Iohannes but I feel compelled to respond. While I do not know of a specific scriptural passage that might apply (although you will find the
phrase in a Latin Vulgate translation of, for example, Ezekiel 47), it is known that the practice of facing
ad orientem goes back to Apostolic times.
Here is a
link to an interview with our Holy Father when he was known as Cardinal Ratzinger, Prefect for the CDF. An excerpt:
Interviewer: And that sense of sacrifice and worship that you’ve talked about so eloquently, how do you see that being restored concretely? Will we see a return to the
ad orientem posture, facing the East, the priest facing away from the people during the Canon?
**Cardinal:**
Versus orientem, I would say could be a help because it is really a tradition from the Apostolic time, and it’s not only a norm, but it’s an expression also of the cosmical dimension and of the historical dimension of the liturgy. We are celebrating with the cosmos, with the world. It’s the direction of the future of the world, of our history represented in the sun and in the cosmical realities. I think today this new discovering of our relation with the created world can be understood also from the people, better than perhaps 20 years ago. And also, it’s a common direction – priest and people are in common oriented to the Lord. So, I think it could be a help. Always external gestures are not simply a remedy in itself, but could be a help because it’s a very classical interpretation of what is the direction of the liturgy.