SB 1.9.44

sampadyamānam ājñāya
 bhīṣmaṁ brahmaṇi niṣkale
sarve babhūvus te tūṣṇīṁ
 vayāṁsīva dinātyaye
Word for word: 
sampadyamānam — having merged into; ājñāya — after knowing this; bhīṣmam — about Śrī Bhīṣmadeva; brahmaṇi — into the Supreme Absolute; niṣkale — unlimited; sarve — all present; babhūvuḥ te — all of them became; tūṣṇīm — silent; vayāṁsi iva — like birds; dina-atyaye — at the end of the day.
Translation: 
Knowing that Bhīṣmadeva had merged into the unlimited eternity of the Supreme Absolute, all present there became silent like birds at the end of the day.
Purport: 

To enter into or to become merged into the unlimited eternity of the Supreme Absolute means to enter the original home of the living being. The living beings are all component parts and parcels of the Absolute Personality of Godhead, and therefore they are eternally related with Him as the servitor and the served. The Lord is served by all His parts and parcels, as the complete machine is served by its parts and parcels. Any part of the machine removed from the whole is no longer important. Similarly, any part and parcel of the Absolute detached from the service of the Lord is useless. The living beings who are in the material world are all disintegrated parts and parcels of the supreme whole, and they are no longer as important as the original parts and parcels. There are, however, more integrated living beings who are eternally liberated. The material energy of the Lord, called Durgā-śakti, or the superintendent of the prison house, takes charge of the disintegrated parts and parcels, and thus they undergo a conditioned life under the laws of material nature. When the living being becomes conscious of this fact, he tries to go back home, back to Godhead, and thus the spiritual urge of the living being begins. This spiritual urge is called brahma-jijñāsā, or inquiry about Brahman. Principally this brahma-jijñāsā is successful by knowledge, renunciation and devotional service to the Lord. Jñāna, or knowledge, means knowledge of everything of Brahman, the Supreme; renunciation means detachment of material affection, and devotional service is the revival by practice of the original position of the living being. The successful living beings who are eligible to enter into the realm of the Absolute are called the jñānīs, the yogīs and the bhaktas. The jñānīs and yogīs enter into the impersonal rays of the Supreme, but the bhaktas enter into the spiritual planets known as the Vaikuṇṭhas. In these spiritual planets the Supreme Lord as Nārāyaṇa predominates, and the healthy, unconditioned living beings live there by rendering loving service to the Lord in the capacity of servant, friend, parents and fiancee. There the unconditioned living beings enjoy life in full freedom with the Lord, whereas the impersonalist jñānīs and yogīs enter into the impersonal glowing effulgence of the Vaikuṇṭha planets. The Vaikuṇṭha planets are all self-illuminating like the sun, and the rays of the Vaikuṇṭha planets are called the brahmajyoti. The brahmajyoti is spread unlimitedly, and the material world is but a covered portion of an insignificant part of the same brahmajyoti. This covering is temporary, and therefore it is a sort of illusion.

Bhīṣmadeva, as a pure devotee of the Lord, entered the spiritual realm in one of the Vaikuṇṭha planets where the Lord in His eternal form of Pārtha-sārathi predominates over the unconditioned living beings who are constantly engaged in the service of the Lord. The love and affection which bind the Lord and devotee are exhibited in the case of Bhīṣmadeva. Bhīṣmadeva never forgot the Lord in His transcendental feature as the pārtha-sārathi, and the Lord was present personally before Bhīṣmadeva while he was passing to the transcendental world. That is the highest perfection of life.