PURPORT

In the Bhagavad-gita it is said that the brahmajyoti or the glowing effulgence transcendental is resting on Lord Sri Krsna. In other words, the glowing effulgence known as brahmatejas is nothing but the rays of the Lord, just as the sun rays are rays of the sun disc. So this Brahma weapon also, although materially irresistible, could not surpass the supreme strength of the Lord. The weapon called brahmasiras, released by Asvatthama, was neutralized and foiled by Lord Sri Krsna by His own energy; that is to say. He did not wait for any other's help because He is absolute.