Origen's Commentary on the Gospel of John

Further, the Only-begotten is the truth, because He embraces in Himself according to the Father’s will the whole reason of all things, and that with perfect clearness, and being the truth communicates to each creature in proportion to its worthiness. And should any one enquire whether all that the Father knows, according to the depth of His riches and His wisdom and His knowledge, is known to our Saviour also, and should he, imagining that he will thereby glorify the Father, show that some things known to the Father are unknown to the Son, although He might have had an equal share of the apprehensions of the unbegotten God, we must remind him that it is from His being the truth that He is Saviour, and add that if He is the truth complete, then there is nothing true which He does not know; truth must not limp for the want of the things which, according to those persons, are known to the Father only. Or else let it be shown that some things are known to which the name of truth does not apply, but which are above the truth.