9 But if any lover of strife contradict what I have said, and also what the apostle affirms, that “we know in part, and prophesy in part,” and imagine that he has acquired not a partial, but a universal, knowledge of all that exists, — being such an one as Valentinus, or Ptolemæus, or Basilides, or any other of those who maintain that they have searched out the deep things of God—let him not (arraying himself in vainglory) boast that he has acquired greater knowledge than others with respect to those things which are invisible, or cannot be placed under our observation; but let him, by making diligent inquiry, and obtaining information from the Father, tell us the reasons (which we know not) of those things which are in this world, — as, for instance, the number of hairs on his own head, and the sparrows which are captured day by day, and such other points with which we are not previously acquainted—so that we may credit him also with respect to more important points.
But if those who are perfect do not yet understand the very things in their hands, and at their feet, and before their eyes, and on the earth, and especially the rule followed with respect to the hairs of their head, how can we believe them regarding things spiritual, and super-celestial, and those which, with a vain confidence, they assert to be above God? So much, then, I have said concerning numbers, and names, and syllables, and questions respecting such things as are above our comprehension, and concerning their improper expositions of the parables: [I add no more on these points,] since you yourself may enlarge upon them.
Source: Adversus haereses (New Advent)