Hilary of Poitiers

He orders them to await the promise of the Father, which has been heard from his mouth. Certainly, the discourse even now is concerned with the promise of his Father. Consequently, the manifestation of the Spirit is through the effects which these powers produce. [Awaiting the promise of the Father,] the gift of the Spirit is not hidden where there is the word of wisdom and where the words of life are heard. The effects of the powers produced by the Spirit are not fully manifest where there is the [rational] perception of the divine knowledge in order that we may not be like the animals, unaware of the author of our life through our ignorance of God, nor even through our faith in God in order that we may not be outside the gospel of God by not believing the gospel of God. The Spirit is not manifested only through the gift of healing in order that by the cure of infirmities we may render testimony to the grace of him who has granted these gifts; or through the performance of miracles in order that the power of God may be recognized in what we are doing; or through prophecy in order that through our knowledge of the doctrine it may be known that we have been taught by God; or through the distinguishing of spirits in order that we may perceive whether anyone speaks through a holy or an evil spirit; or through the various kinds of languages in order that the sermons in these languages may be offered as a sign of the Holy Spirit who has been given; or in the interpretation of the languages in order that the faith of the hearers might not be endangered through ignorance, since the interpreter of a language makes it intelligible for those who are not familiar with the language. Rather it is through all the diversities of these gifts that the effects of the Spirit are poured out for the profit of everyone.

The Son is not lacking in the knowledge of anything that the Father knows, and the Son is not ignorant, because the Father alone knows, since the Father and the Son remain in the unity of the nature. What the Son, in whom all the treasures of wisdom and knowledge are hidden, does not know is in harmony with the divine plan for maintaining silence. The Lord bore testimony to this when he replied to the apostles who had questioned him about the times, “It is not for you to know the times or dates which the Father has fixed by his own authority.”The knowledge is denied them. Not only is it denied, but they are forbidden to be anxious about the knowledge, since it is not for them to know these times. Naturally, after the resurrection, they now interrogate him about the times, since they had been informed previously when they broached the question, that not even the Son knows, and they could not believe that the Son did not know in the literal meaning of the term, because they again question him as one who does not know. Since they are aware that the mystery of not knowing is according to the divine plan for maintaining silence, they conclude that now, after the resurrection, the time for speaking has at length arrived, and they bring forth their questions.
And the Son does not tell them that he does not know but that it is not for them to know, because the Father has settled this matter by his own authority. Consequently, if the apostles realize that this statement, that the Son does not know, is in keeping with the plan of salvation and is not a weakness, shall we assert that the Son, therefore, does not know the day because he is not God? God the Father has determined it by his own authority, therefore, in order that it may not come to the knowledge of our human comprehension, and the Son, when previously interrogated, had said that he did not know and now he does not make the same reply that he does not know, but that it is not for them to know, and that the Father, however, has decided upon these times not in his knowledge but in his authority. Since the day and moment are included in the idea of time, it is impossible to believe that the day and moment for restoring the kingdom of Israel is unknown to him who is to restore it. But, to lead us to the knowledge of his birth through the Father’s unique power, he answered that it was known to him and, while revealing that the right to acquire this knowledge had not been conferred on them, he declared that this knowledge itself is dependent upon the mystery of the Father’s authority.