As stated personally by the Supreme Personality of Godhead in the Bhagavad-gītā, He is realized proportionately by transcendentalists as Brahman, Paramātmā and the Supreme Personality of Godhead. Here, in confirmation of the same statement, Lord Kṛṣṇa, who awards the impersonalist the pleasure of Brahman realization by His bodily effulgence, also gives pleasure to the devotees as the Supreme Personality of Godhead. Those who are under the spell of the external energy, māyā, take Him only as a beautiful child. Yet He gave full transcendental pleasure to the cowherd boys who played with Him. Only after accumulating heaps of pious activities were those boys promoted to personally associate with the Supreme Personality of Godhead. Who can estimate the transcendental fortune of the residents of Vṛndāvana? They were personally seeing the Supreme Personality of Godhead face to face, He whom many yogīs cannot find even after undergoing severe austerities, although He is sitting within their hearts. This is confirmed in the Brahma-saṁhitā: One may search for Kṛṣṇa, the Supreme Personality of Godhead, through the pages of the Vedas and Upaniṣads, but it is difficult to find Him there. However, one who is fortunate enough to associate with a devotee can see the Supreme Personality of Godhead face to face. After accumulating pious activities in many, many previous lives, the cowherd boys were seeing Kṛṣṇa face to face and playing with Him as friends. They could not understand that Kṛṣṇa is the Supreme Personality of Godhead, but they were playing as intimate friends with intense love for Him.
When Lord Kṛṣṇa was enjoying His childhood pastimes with His boyfriends, one Aghāsura demon became very impatient. He was unable to tolerate seeing Kṛṣṇa play so happily, and therefore he appeared before the boys intending to kill them all. This Aghāsura was so dangerous that even the denizens of heaven were afraid of him. Although the denizens of heaven drank nectar daily to prolong their lives, they were afraid of this Aghāsura and were wondering, "When will the demon be killed?" The denizens used to drink nectar to become immortal, but actually they were not confident of their immortality. On the other hand, the boys who were playing with Kṛṣṇa had no fear of the demons. They were free of fear. Any material arrangement for protecting oneself from death is always unsure, but if one is in Kṛṣṇa consciousness, then immortality is confidently assured.
The demon Aghāsura appeared before Kṛṣṇa and His friends. Aghāsura happened to be the younger brother of Pūtanā and Bakāsura, and he thought, "Kṛṣṇa has killed my brother and sister. Now I shall kill Him along with all His friends and calves." Aghāsura was instigated by Kaṁsa, so he had come with determination. Aghāsura also thought that when he would offer grains and water in memory of his brother and sister and kill Kṛṣṇa and all the cowherd boys, then automatically all the inhabitants of Vṛndāvana would die. Generally, for the householders, the children are the life and breath force. When all the children die, then naturally the parents also die on account of strong affection for them.
Aghāsura, thus deciding to kill all the inhabitants of Vṛndāvana, expanded himself by the yogic siddhi called mahimā. The demons are generally expert in achieving almost all kinds of mystic powers. In the yoga system, by the perfection called mahimā-siddhi, one can expand himself as he desires. The demon Aghāsura expanded himself up to eight miles and assumed the shape of a very fat serpent. Having attained this wonderful body, he stretched his mouth open just like a mountain cave. Desiring to swallow all the boys at once, including Kṛṣṇa and Balarāma, he sat on the path.
The demon in the shape of a big fat serpent expanded his lips from land to sky; his lower lip was touching the ground, and his upper lip was touching the clouds. His jaws appeared like a big mountain cave, without limitation, and his teeth appeared just like mountain summits. His tongue appeared to be a broad traffic way, and he was breathing just like a hurricane. His eyes were blazing like fire. At first the boys thought that the demon was a statue, but after examining it they saw that it was a big serpent lying down on the road and widening his mouth. The boys began to talk among themselves: "Dear friends, this figure appears to be a great animal, and he is sitting in such a posture just to swallow us all. Just see—is it not a big snake that has widened his mouth to eat all of us?"
One of them said, “Yes, what you say is true. This animal's upper lip appears to be just like the sunshine, and its lower lip is just like the reflection of red sunshine on the ground. Dear friends, just look to the right- and left-hand side of the mouth of the animal. Its mouth appears to be like a big mountain cave, and its height cannot be estimated. The chin is also raised just like a mountain summit. That long highway appears to be its tongue, and inside the mouth it is as dark as in a mountain cave. The hot wind that is blowing like a hurricane is his breathing, and the fishy bad smell coming out from his mouth is the smell of his intestines.”
Then they further consulted among themselves: "If we all at one time entered into the mouth of this great serpent, how could it possibly swallow all of us? And even if it were to swallow all of us at once, it could not swallow Kṛṣṇa. Kṛṣṇa will immediately kill him, as He did Bakāsura." Talking in this way, all the boys looked at the beautiful lotuslike face of Kṛṣṇa, and they began to clap and smile. And so they marched forward and entered the mouth of the gigantic serpent.