Lord Brahmā himself has no material cause. He is the cause of the creation of all living beings and is the greatest among all the demigods. Yet even Brahmā is always suffering agitation of the mind on account of the duties he has to perform; therefore, when he was questioned by his sons headed by Sanaka, who were born from his mind, about the means for driving away desires for sense gratification, he was incapable of giving them an answer. In order to receive some insight into this matter, he took shelter of the Supreme Personality of Godhead, whereupon the Supreme Lord appeared before him in the form of the swan incarnation, Lord Haṁsa. Lord Haṁsa proceeded to give instructions about the categorical identity of the self, the different states of consciousness (wakeful awareness, sleep and deep sleep) and the means for conquering over material existence. The sages headed by Sanaka became freed from all their doubts by hearing the words of the Lord and worshiped Him with pure devotion in mature love of God.