The idea is that because God and His knowledge are both unlimited, as soon as God is cognizant of some of His energies, He perceives that He has still more energies. In this way, both His energies and His knowledge increase. Because both of them are unlimited, there is no end to the energies and no end to the knowledge with which to understand the energies. God is undoubtedly omniscient, but the personified Vedas say that even God Himself does not know the full extent of His energies. This does not mean that God is not omniscient. When an actual fact is unknown to a certain person, this is called ignorance or lack of knowledge. This is not applicable to God, however, because He knows Himself perfectly. But still, as His energies and activities increase, He also increases His knowledge to understand them. Both are increasing unlimitedly, and there is no end to it. In that sense it can be said that even God Himself does not know the limit of His energies and qualities.
How God is unlimited in His expansion of energies and activities can be roughly calculated by any sane and sober living entity. It is said in the Vedic literature that innumerable universes issue forth when Mahā-Viṣṇu exhales in His yoga-nidrā and that innumerable universes enter His body when He inhales. We have to imagine that these universes, which according to our limited knowledge are expanded unlimitedly, are so great that the gross and subtle ingredients—the five elements of the cosmic manifestation, namely earth, water, fire, air and sky, along with the total material energy and false ego—are not only within the universe but cover the universe in seven layers, each layer ten times bigger than the previous one. In this way, each and every universe is very securely packed, and there are numberless universes. All these universes float within the innumerable pores of the transcendental body of Mahā-Viṣṇu. It is stated that just as the atoms and particles of dust are floating within the air along with the birds and their number cannot be calculated, so innumerable universes are floating within the pores of the transcendental body of the Lord. For this reason, the Vedas say that God is beyond the grasp of our knowledge. Avāṅ-mānasa-gocara: to understand the length and breadth of God is beyond the jurisdiction of our mental speculation. Therefore, a person who is actually learned and sane does not claim to be God but tries to understand God, making distinctions between spirit and matter. By such careful discrimination, one can clearly understand that the Supreme Soul is transcendental to both the superior and inferior energies, although He has a direct connection with both. In the Bhagavad-gītā, Lord Kṛṣṇa explains that although everything is resting on His energy, He is different or separate from the energy.
Nature and the living entities are sometimes designated as prakṛti and puruṣa respectively. The whole cosmic manifestation is an amalgamation of prakṛti and puruṣa. Nature is the ingredient cause, and the living entities are the effective cause. These two causes combine together, and the effect is this cosmic manifestation. When one is fortunate enough to come to the right conclusion about this cosmic manifestation and everything going on within it, he knows it to be caused directly and indirectly by the Supreme Personality of Godhead Himself. It is concluded in the Brahma-saṁhitā, therefore, īśvaraḥ paramaḥ kṛṣṇaḥ sac-cid-ānanda-vigrahaḥ / anādir ādir govindaḥ sarva-kāraṇa-kāraṇam (Bs. 5.1). After much deliberation and consideration, when one has attained the perfection of knowledge, one comes to the conclusion that Kṛṣṇa, or God, is the original cause of all causes. Instead of speculating about the measurement of God—whether He is so long or so wide—or falsely philosophizing, one should come to the conclusion of the Brahma-saṁhitā: "Kṛṣṇa, or God, is sarva-kāraṇa-kāraṇam (Bs. 5.1), the cause of all causes." That is the perfection of knowledge.