8 Moreover, they possess no proof of their system, which has but recently been invented by them, sometimes resting upon certain numbers, sometimes on syllables, and sometimes, again, on names; and there are occasions, too, when, by means of those letters which are contained in letters, by parables not properly interpreted, or by certain [baseless] conjectures, they strive to establish that fabulous account which they have devised. For if any one should inquire the reason why the Father, who has fellowship with the Son in all things, has been declared by the Lord alone to know the hour and the day [of judgment], he will find at present no more suitable, or becoming, or safe reason than this (since, indeed, the Lord is the only true Master), that we may learn through Him that the Father is above all things.
For “the Father,” says He, “is greater than I.” The Father, therefore, has been declared by our Lord to excel with respect to knowledge; for this reason, that we, too, as long as we are connected with the scheme of things in this world, should leave perfect knowledge, and such questions [as have been mentioned], to God, and should not by any chance, while we seek to investigate the sublime nature of the Father, fall into the danger of starting the question whether there is another God above God.
Source: Adversus haereses (New Advent)