Ante-Nicene Fathers, Vol IX:
Origen's Commentary on the Gospel of Matthew.: Chapter XXXVI

36.  Concerning the Transfiguration of the Saviour.

“Now after six days,” according to Matthew and Mark, 5779 “He taketh with him Peter and James and John his brother, and leads them up into a high mountain apart, and was transfigured before them.”  Now, also, let it be granted, before the exposition that occurs to us in relation to these things, that this took place long ago, and according to the letter.  But it seems to me, that those who are led up by Jesus into the high mountain, and are deemed worthy of beholding His transfiguration apart, are not without purpose led up six days after the discourses previously spoken.  For since in six days—the perfect number—the whole world,—this perfect work of art,—was made, on this account I think that he who transcends all the things of the world by beholding no longer the things which are seen, for they are temporal, but already the things which not seen, and only the things which are not seen, because that they are eternal, is represented in the words, “After six days Jesus took up with Him” certain persons.  If therefore any one of us wishes to be taken by Jesus, and led up by Him into the high mountain, and be deemed worthy of beholding His transfiguration apart, let him pass beyond the six days, because he no longer beholds the things which are seen, nor longer loves the world, nor the things in the world, 5780 nor lusts after any worldly lust, which is the lust of bodies, and of the riches of the body, and of the glory which is after the flesh, and whatever things whose nature it is to distract and drag away the soul from the things which are better and diviner, and bring it down and fix it fast to the deceit of this age, in wealth and glory, and the rest of the lusts which are the foes of truth.  For when he has passed through the six days, as we have p. 470 said, he will keep a new Sabbath, rejoicing in the lofty mountain, because he sees Jesus transfigured before him; for the Word has different forms, as He appears to each as is expedient for the beholder, and is manifested to no one beyond the capacity of the beholder.

Footnotes

Matt. 17:1, Mark 9:2.

1 John ii. 15.