Bhasma or vibhuti(Holy ashes) – Shiva Purana

Vibhuti is a word in Sanskrit which means greatness, wealth, prosperity, super human power, splendour, holy ashes etc. Vibhuti is also called Bhasma (ash). Generally, it is used to denote the sacred ash which is made of burnt special kind of dried wood or cow dung in Agamic rituals. In yajna, the offerings like ghee, milk, curd, rice, holy twigs etc., are made to Agni who carries the offerings to the respective devata in a yajna. The residue left over which is white in colour is considered as Vibhuti and is given to the devotees as prasad for daily use to please Lord Shiva.
 
Vedic scriptures say as follows “Lalaata Shoonyam Smashaana Tulyam”, which means that “an empty forehead is comparable to a cemetery”. Shaivites or Shiva worshippers apply vibhuti on their forehead and other body parts. Vibhuti on forehead is worn along with red tilaka also. Vibhuti relates to Shiva and Red tilaka to Shakti. It reminds that Shiva and Shakti form the universe and everything is though the union of Shiva and Shakti.
Chapter 24, Vidhyeshwara Samhita of Shiva Purana elaborates Bhasma or Vibhuti hereunder.
 
Spiritual, Religious & Medicinal Significance of Vibhuti:

1. With the three middle fingers, take the ashes and apply the Tripuṇḍra on the forehead. It would give worldly pleasures and salvation. For each of the three lines there are nine deities.
   1. The nine deities of the first line are: —The syllable “A” of pranav AUM, Garhapatya fire (sacrificial fire), Earth, Dharma, the attribute Rajas, Rigveda, Kriya Shakti (the power to action), Prataḥsavana (morning rituals) and Mahadeva.
   2. The nine deities of the second line are: —The syllable “U”, Dakṣiṇa fire (sacrificial fire), the principle of Ether, Attribute Sattva, Yajurveda, Madhyandina Savana (midday rituals), Iccha Shakti (the will-power), the Antar-atman (the immanent soul) and Maheshwara.
   3. The nine deities of the third line are: —The syllable “M”, Ahavaniya (sacrificial) fire, the supreme soul, the attribute Tamas, heaven, Jnana Shakti, Samaveda, the third Savana (evening rituals) and Shiva. (Shlokas 87-94)
2. He who wears Tripuṇḍra enjoy all worldly pleasures and live long without any disease. At the end of the span of his life he will have a peaceful death. (Shlokas 67-68)
3. A man who wears the Tripuṇḍra while performing Sraddha, Yajna, Japa, Homa, Vaisvadeva and the worship of the deities is a purified soul and he conquers even death. (Shlokas 75)
4. Applying holy ash is said to regulate all the 7 chakras in the body which is the basis for good health. Illness is said to be mainly due to the imbalance of our seven glands (chakras).

 
Types of Vibhuti:
The holy ashes of auspicious nature are of two types - Mahabhasma (Great ashes) and the second is known as Svalpa (the little).

1. The Mahabhasma is of three types - Srauta, (Vedic), Smarta (resulting from Smṛti rites) and Laukika (prepared from ordinary fire).
2. The Svalpa is the ordinary ash.
3. The Srauta and the Smarta ashes are to be used only by the trained Brahmins (Dvija). The Dvija should apply the holy ashes by repeating mantras.
4. The Laukika can be used by everyone. The others can simply apply without any mantra. (Shlokas 2-5)

How to apply Vibhuti:

1. After performing the sacred rites of Siva in the fire, the devotee who has realised the Self shall smear the forehead with the ashes repeating the prescribed mantra. He who makes Tripuṇḍra with white ashes during the three Sandhyas every day becomes free from all sins and rejoices with Shiva. One should not recite panchakshar mantra without applying holy ashes on the body. (Shlokas 19-22)
2. Brahmins and Kshatriyas shall apply the holy ashes over the parts of the body by reciting mantra “Ma nastoke..” etc.; Vaisya by reciting the mantra “Om Tryambaka..” and a Sudra with the five-syllabled mantra – Panchakshar”. (Shlokas 33-34)
3. These lines are to be made either in thirty-two places, or half of that—in sixteen places, or in eight places or in five places.
   1. The thirty-two places are: —head, forehead, two ears, two eyes, two noses, mouth, neck, two arms, two elbows, two wrists, chest, two sides, navel, two testicles, two thighs, two knees, two calves, two heels and two feet.
   2. The sixteen parts mentioned before are: —head, forehead, neck, two shoulders, two arms, two elbows, two wrists, chest, navel, two sides and back.
   3. The private parts, forehead, the excellent pair of ears, two shoulders, chest and navel—these are the eight parts of the body.
   4. Or the five parts are: —forehead, two arms, chest and navel. While applying holy ashes, the names of respective deities are uttered.
   5. If incapable of applying the whole body with the holy ashes he shall have the Tripuṇḍra on the forehead alone, remembering lord Shiva, the three-eyed, the support of the three Guṇas and the progenitor of the three devas by repeating “Namaḥ Shivay” (obeisance to Shiva). He shall have Tripuṇḍra in the sides saying “Ishabhyam Namah” (obeisance to Shiva and the goddess) and in the forearms by saying “Bijabhyam Namaḥ” (obeisance to the generating seeds). He shall apply the ashes on lower part by saying “Namaḥ Pitṛbhyam” (obeisance to the manes), on upper part by saying “Namaḥ Umesabhyam (obeisance to Uma and Isha) and on the back and the back of the head by saying “Namaḥ Bhimaya (obeisance to Bhima). (Shlokas 98-116)

 
Reference: Vidhyeshwara Samhita chapter 24 of Shiv Purana