Text 18]
Brahmā Stealing the Boys and Calves
19
PURPORT
Although Kṛṣṇa is  viśva-vit , the knower of everything happening in the entire cosmic manifestation, as an innocent child He showed ignorance of Brahmā's actions, although He could immediately understand that these were the doings of Brahmā. This pastime is called  brahma-vimohana , the bewilderment of Brahmā. Brahmā was already bewildered by Kṛṣṇa's activities as an innocent child, and now he would be further bewildered.
TEXT 18
ततः कृष्णो मुदं कर्तुं तन्मातृणां च कस्य च । उभयायितमात्मानं चक्रे विश्वकृदीश्वरः ॥१८॥
tataḥ kṛṣṇo mudaṁ kartuṁ tan-mātṝṇāṁ ca kasya ca ubhayāyitam ātmānaṁ cakre viśva-kṛd īśvaraḥ
tataḥ —thereafter;  kṛṣṇaḥ —the Supreme Personality of Godhead;  mudam —pleasure;  kartum —to create;  tat-mātṝṇāṁ ca —of the mothers of the cowherd boys and calves;  kasya ca —and (the pleasure) of Brahmā;  ubhayāyitam —expansion, both as the calves and as the cowherd boys;  ātmānam —Himself;  cakre —did;  viśva-kṛt īśvaraḥ —it was not difficult for Him, for He is the creator of the whole cosmic manifestation.
TRANSLATION
Thereafter, just to create pleasure both for Brahmā and for the mothers of the calves and cowherd boys, Kṛṣṇa, the creator of the entire cosmic manifestation, expanded Himself as calves and boys.
PURPORT
Although Brahmā was already entangled in bewilderment, he wanted to show his power to the cowherd boys; but after he took away the boys and their calves and returned to his abode, Kṛṣṇa created further