St. Gregory the Dialogist ca. 540-604
And that both the elect and reprobate, whose life and conversation hath been alike, shall after death be carried to like places, the saying of our Saviour doth teach us, though we had no examples to prove the same; for of the elect himself saith in the Gospel: In the house of my Father there be many mansions. For if there were not inequality of rewards in the everlasting felicity of heaven, then were there not many mansions, but rather one: wherefore there be many mansions, in which divers orders and degrees of God’s saints be distinguished, who in common do all rejoice of the society and fellowship of their merits, and yet all they that laboured receive one penny, though they remain in distinct mansions: because the felicity and joy which there they possess is one, and the reward, which by divers and unequal good works they receive is not one but divers… (Dialogues Bk. 4.35)
St. Isaac the Syrian ca. 7th cent.
The Saviour calls the ‘many mansions’ of His Father’s house the noetic levels of those who dwell in that land, that is, the distinctions of the gifts and the spiritual degrees which they noetically take delight in, as well as the diversity of the ranks of the gifts. But by this He did not mean that each person yonder will be confined in his existence by a seperate spatial dwelling and by the manifest, distinguishing mark of the diverse placement of each man’s abode. Rather, it resembles how each one of us derives a unique benefit from this visible sun though a single enjoyment of it common to all, each according to the clarity of his eyesight and the ability of his pupils to contain the sun’s constant effusion of light…In the same manner, those who at the appointed time will be deemed worthy of that realm will dwell in one abode which will not be divided into a multitude of seperate parts. And according to the rank of his discipline each man draws delight for himself from one noetic Sun in one air, one place, one dwelling, one vision, and one outward appearance. He whose measure is less will not see the great measure of his neighbor’s rank, lest he should think that this arises from the multitude of his neighbor’s gifts and the fewness of his own, and this very thing should become for him a cause of sadness and mental anguish. Far be it that one should suppose such a thing to occur in that realm of delights! Each man inwardly takes delight in the gift and the lofty rank whereof he has been deemed worthy. (The Spiritual World of Isaac the Syrian by Hilarion Alfeyev, pp. 277-278)