Of the four directions, the North, South, East, and West, who would not at once admit that the East clearly indicates the duty of praying with the face turned towards it with the symbolic suggestion that the soul is looking upon the dawn of the true light?
Should anyone, however, prefer to direct his intercessions according to the aperture of the house, whichever way the doors of the house may face, saying that the sight of heaven appeals to one with a certain attraction greater than the view of the wall, and the eastward part of the house having no opening, we may say to him that since it is by human arrangement that houses are open in this or that direction but by nature that the East is preferred to all the other directions, the natural is to be set before the artificial. Besides, on that view why should one who wished to pray when in the open country pray to the East in preference to the West? If, in the one case it is reasonable to prefer the East, why should the same not be done in every case? Enough on that subject.
Origen
On Prayer
Chapter XX