Afterwards (those who are in the material world, must first of all know how the external energy of the Lord is working) one may try to enter into the activities of His internal energy

Expressions researched:
"afterwards one may try to enter into the activities of His internal energy"

Srimad-Bhagavatam

SB Canto 2

But neither the King nor the great speaker of Śrīmad-Bhāgavatam jumped up like the organizers of Bhāgavatam; both of them proceeded systematically, so that both future readers and hearers might take lessons from the example of the procedure of reciting Śrīmad-Bhāgavatam. Those who are in control of the external energy of the Lord, or in other words those who are in the material world, must first of all know how the external energy of the Lord is working under the direction of the Supreme Personality, and afterwards one may try to enter into the activities of His internal energy.

SB 2.4.6, Translation and Purport

I beg to know from you how the Personality of Godhead, by His personal energies, creates these phenomenal universes as they are, which are inconceivable even to the great demigods.

In every inquisitive mind the important question of the creation of the phenomenal world arises, and therefore for a personality like Mahārāja Parīkṣit, who was to know all the activities of the Lord from his spiritual master, such an inquiry is not uncommon. For every unknown thing, we have to learn and inquire from a learned personality.