The story goes something like this that the four sons, of Brahma, Sanaka, Sanandana, Sanatana, Sanat Kumara, did austere prayer and meditation to arrive at what exactly is the Supreme Truth. This was something which was perplexing them and they had done a lot of analysis on the same , but were still not able to arrive at the correct answer. What is the greatest truth in this entire universe , who could answer this question for them ??
Finally, they came to the conclusion that if anyone can answer this question of theirs it has got to be the Supreme Commander of this entire Universe , Lord Shiva Himself !! Having decided this , they came to Lord Shiva so as to get the knowledge of the Truth, but when they reached him , they found him sitting under the banyan tree, and the four sages also quietly sat down around Him.
Lord Shiva was sitting in a yoga stance without even uttering a single word , and the the four sages got all their doubts cleared just by that posture. The form in which God appeared as a Supreme Guide is the form of wisdom known as Dakshinamurthi.
In fact the posture of the Guru is a thing to be thought about deeply always, to understand what it signifies , and the rest will all become clear by itself .
Does that make sense , the postures of tranquility and peaceful meditation is the ultimate truth, get immersed so much in the supreme power , that nirvana is an absolute certainity , the path to salvation !!