Mark 13:32

(de Trin. ix) This ignorance of the day and hour is urged against the Only-Begotten God, as if, God born of God had not the same perfection of nature as God. But first, let common sense decide whether it is credible that He, who is the cause that all things are, and are to be, should be ignorant of any out of all these things. For how can it be beyond the knowledge of that nature, by which and in which that which is to be done is contained? And can He be ignorant of that day, which is the day of His own Advent? Human substances foreknow as far as they can what they intend to do, and the knowledge of what is to be done, follows upon the will to act. How then can the Lord of glory, from ignorance of the day of His coming, be believed to be of that imperfect nature, which has on it a necessity of coming, and has not attained to the knowledge of its own advent? But again, how much more room for blasphemy will there be, if a feeling of envy is ascribed to God the Father, in that He has withheld the knowledge of His beatitude from Him to whom He gave a foreknowledge of His death. But if there are in Him all the treasures of knowledge, He is not ignorant of this day; rather we ought to remember that the treasures of wisdom in Him are hidden; His ignorance therefore must be connected with the hiding of the treasures of wisdom, which are in Him. (Col. 2:3) For in all cases, in which God declares Himself ignorant, He is not under the power of ignorance, but either it is not a fit time for speaking, or it is an economy of not acting. But if God is said then to have known that Abraham loved Him, when He did not hide that His knowledge from Abraham, it follows, that the Father is said to know the day, because He did not hide it from the Son. (Gen. 22:12) If therefore the Son knew not the day, it is a Sacrament of His being silent, as on the contrary the Father alone is said to know, because He is not silent. But God forbid that any new and bodily changes should be ascribed to the Father or the Son. Lastly, lest He should be said to be ignorant from weakness, He has immediately added, Take ye heed, watch and pray, for ye know not when the time is.

The Lord wishing to prevent His disciples from asking about that day and hour, says, But of that day and that hour knoweth no man, no, not the angels which are in heaven, neither the Son, but the Father. For if He had said, I know, but I will not reveal it to you, He would have saddened them not a little; but He acted more wisely, and prevents their asking such a question, lest they should importune Him, by saying, neither the Angels nor I.