Srimad Bhagavatam Canto 04, Chapter 06, Text 39

SB 4.6.39

tam brahma-nirvana-samadhim asritam
vyupasritam girisam yoga-kaksam
sa-loka-pala munayo manunam
adyam manum prañjalayah pranemuh
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
All the sages and demigods, headed by Indra, offered their respectful obeisances unto Lord Siva with folded hands. Lord Siva was dressed in saffron garments and absorbed in trance, thus appearing to be the foremost of all sages.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
In this verse the word brahmananda is significant. This brahmananda, or brahma-nirvana, is explained by Prahlada Maharaja. When one is completely absorbed in the adhoksaja, the Supreme Personality of Godhead, who is beyond the sense perception of materialistic persons, one is situated in brahmananda.
It is impossible to conceive of the existence, name, form, quality and pastimes of the Supreme Personality of Godhead because He is transcendentally situated beyond the conception of materialistic persons. Because materialists cannot imagine or conceive of the Supreme Personality of Godhead, they may think that God is dead, but factually He is always existing in His sac-cid-ananda-vigraha, His eternal form. Constant meditation concentrated on the form of the Lord is called samadhi ecstasy or trance. Samadhi means particularly concentrated attention, so one who has achieved the qualification of always meditating on the Personality of Godhead is to be understood to be always in trance and enjoying brahma-nirvana, or brahmananda. Lord Siva exhibited those symptoms, and therefore it is stated that he was absorbed in brahmananda.
Another significant word is yoga-kaksam. Yoga-kaksa is the sitting posture in which the left thigh is fixed under one’s tightly knotted saffron-colored garment. Also the words manunam adyam are significant here because they mean a philosopher, or one who is thoughtful and can think very nicely. Such a man is called manu. Lord Siva is described in this verse as the chief of all thinkers. Lord Siva, of course, does not engage in useless mental speculation, but as stated in the previous verse, he is always thoughtful regarding how to deliver the demons from their fallen condition of life. It is said that during the advent of Lord Caitanya, Sadasiva appeared as Advaita Prabhu, and Advaita Prabhu’s chief concern was to elevate the fallen conditioned souls to the platform of devotional service to Lord Krsna. Since people were engaged in useless occupations which would continue their material existence, Lord Siva, in the form of Lord Advaita, appealed to the Supreme Lord to appear as Lord Caitanya to deliver these illusioned souls. Actually Lord Caitanya appeared on the request of Lord Advaita. Similarly, Lord Siva has a sampradaya, the Rudra sampradaya. He is always thinking about the deliverance of the fallen souls, as exhibited by Lord Advaita Prabhu.
Srimad Bhagavatam Canto 04, Chapter 06, Text 38
Srimad Bhagavatam Canto 04, Chapter 06, Text 40