Kṛṣṇa explains that all the purposes served by a small well are naturally served by a vast reservoir of water. Similarly, all the benefits of the various Vedic rituals are automatically achieved by one who knows the Absolute Truth. You don’t need to visit every small pond if you have the ocean. If you have a million dollars, you automatically have ten dollars. Kṛṣṇa is telling Arjuna that he doesn’t need to worry about missing out on various religious merits by not following specific rituals. By connecting with the Source (Kṛṣṇa) and acting in that consciousness, Arjuna fulfills the ultimate goal of all scriptures. The many rules of the Vedas are meant to lead one to this point of surrender and knowledge. Once that point is reached, the rules are surpassed by the reality they were pointing toward.