Each of the four Vedas, the basic scriptures of the Hindus, is divided broadly into two sections: the Mantra and the Brāhmaṇa. The Mantra section contains prayers and hymns. The Brāhmaṇa section deals with the application of these mantras in rituals.
The Adbhuta Brāhmaṇa forms the sixth (and the last) chapter of a bigger work called Ṣaḍviṁśa Brāhmaṇa which itself is the second of the nine Brāhmaṇas of the Sāmaveda, available to us now. Though the first five chapters of the Ṣaḍviṁśa Brāhmaṇa deal with the ceremonies and rituals connected with the Somayāgas, the sixth one makes a comp-lete departure and deals with strange phenomena like ill-omens and the expiatory rites that help offset their effects. It is perhaps due to this reason that this particular section is thus designated (adbhuta wonderful, strange).
There are indications to prove that the Ṣaḍviṁśa Brāhmaṇa originally consisted of only five chapters and the sixth i.e., the Adbhuta Brāhmaṇa was appended to it later.
The entire book deals with adbhuta-śāntis or appeasement of portents, and is divided into twelve khaṇḍas or sections. The various portents indicating imminent dangers are described as being connected with the gods like Indra, Yama, Varuṇa and Viṣṇu; and appropriate śāntis (rites of appeasement of the deities) are also given. The idea seems to be that when these gods are displeased, troubles start and when appeased through appropriate rites, they cease.
The list of portents given is quite long but interesting. Starting from the breaking or damage of household articles for apparently no reason, right up to natural calamities like earthquakes, destruction of crops and the fall of meteors, the list mentions the happening of many unnatural and improbable phenomena also. Among such, it is curious to note that temples shake and the idols of gods laugh, weep, sing, dance or close their eyes! This is a clear indication that temples with idols installed, had already come into being by the time of this Brāhmaṇa.
The śānti rites are usually sacrificial oblations with suitable mantras addressed to the deity that has been displeased.
See also ṢAḌVIṀŚA BRĀHMAṆA.