на himalayanart.org в недавнем обновлении цитируется текст сампута-тантры о четках:
Prayer beads (mala) are a very personal religious article. They can be made of a varying number of beads and of different substances depending on the intended use. Strictly speaking the materials that the beads are made from and the specific number of beads are determined according to the intended type of religious practice to be performed along with the guidelines of the Four Activities. Several Indian Sanskrit texts explain the general creation and uses of the mala such as the Vajra Garbha Lamkara, Samputa and Dakarnava Tantras.
The Four Activities can be differentiated by purpose and visually by appearance, colour and geometric form for palaces, ritual shrines, and the fire hearth. They are also known as the four lower, or common, activities. The higher, or uncommon, activity is the striving for enlightenment. The four lower activities are:
[1] Peaceful
[2] Increasing
[3] Powerful
[4] Wrathful
According to the Samputa Tantra: "In general for accomplishment in Mantrayana the number [of beads for a mala] is fifty [50]. Specifically, for Powerful [activities] the [number is] half of that [25 beads]. For Peaceful [activities the number is] one hundred [100]. Likewise, for Increasing [activities] add eight extra [108 beads]. For Wrathful [activities] it is sixty [beads]."
Prayer Beads & Numbers:
- Mantrayana in General = 50 Beads
Specialized Activities:
- Peaceful Activities = 100 Beads
- Increasing Activities = 108 Beads
- Powerful Activities = 25 Beads
- Wrathful Activities = 60 Beads
In modern times it is common to find prayer beads with numbers such as twenty-one (21), twenty-seven (27) and one hundred and eight (108).
The Samputa Tantra also presents the basic substances of the beads according to the Four Activities. For Peaceful activities and the corresponding colour white, the beads can be of crystal, pearl, bodhi seed, or various types of wood. For the activity of Increasing, yellow colour, the material of the beads can be gold, silver, copper, or lotus seed. For Powerful activities, the colour red, beads of red sandalwood or red coral are used. For Wrathful activities, black in colour, the material is rudraksha seeds, fruit pits, or beads made from human bone. It is commonly said that a bodhi seed mala is good for all four activities in general.
Substances in General: bodhi seed, lotus seed, rudraksha seed, fruit pit, ivory, human bone, buffalo bone, amber, coral, crystal, pearl, lapiz lazuli, wood, white sandalwood, red sandalwood, stone, gold, silver, copper, etc. In rare but specialized cases there can even be prayer beads made of snake vertebrae and other exotic substances. Specific Tantras such as the Hevajra and the twenty-five and fifty chapter Mahakala Tantras will also prescribe malas made from a particular substance for any number of specialized activities. The Hevajra Tantra lists rock crystal, red sandalwood, soap tree wood, human bone, horse bone, Brahmin's bone, elephant bone and buffalo bone.
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"The head bead is also referred to in popular culture as the guru bead and is said to represent the teacher. In early Tibetan texts from the 11th and 12th centuries the head bead was said to represent a stupa and had two parts, a spire shape and a vase shape, without any reference to a teacher."
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