He perceived that mind (manas) is Brahman, for from mind these beings are born; by mind, when born, they live; into mind they enter at their death. Having perceived this, he went again to his father Varuna, saying: 'Sir, teach me Brahman.' He said to him: 'Try to know Brahman by penance, for penance is (the means of knowing) Brahman.' He performed penance. Having performed penance—

In plain words: After more effort, Bhrigu decided that the mind is Brahman, the source of all things, because beings come from the mind, live by it and go back into it. Still not satisfied, he asked his father Varuna again, and Varuna again told him to keep up his discipline, since that is how Brahman is known.