He who has realized oneness with God possesses all knowledge contained in Him. Knowing the Lord as Beginning and End of all beings and worlds, a true Brahmin has knowledge of the hereafter and of the workings of nature on this plane of existence.
The Bhagavad Gita: God talks with Arjuna : royal science of God realization (ed. Self Realization Fellowship Pub, 1995) - ISBN: 9780876120309