In Buddhism, kasiṇa (Pali; Sanskrit: kṛtsna) refers to a class of basic visual objects of meditation. There are ten kasiṇa mentioned in the Pali Tipitaka:
- earth (paṭhavī kasiṇa),
- water (āpo kasiṇa),
- fire (tejo kasiṇa),
- air, wind (vāyo kasiṇa),
- blue, green (nīla kasiṇa),
- yellow (pīta kasiṇa),
- red (lohita kasiṇa),
- white (odāta kasiṇa),
- enclosed space, hole, aperture (ākāsa kasiṇa),
- consciousness (viññāṇa kasiṇa) in the Pali suttas and some other texts; bright light (āloka kasiṇa) according to later sources, such as Buddhaghosa's Visuddhimagga.
The kasiṇa are typically described as a colored disk, with the particular color, properties, dimensions and medium often specified according to the type of kasiṇa. The earth kasiṇa, for instance, is a disk in a red-brown color formed by spreading earth or clay (or another medium producing similar color and texture) on a screen of canvas or another backing material.
Kasiṇa meditation is a concentration meditation (variously known in different traditions as samatha, dhyana, or jhāna meditations), intended to settle the mind of the practitioner and create a foundation for further practices of meditation. In the early stages of kasiṇa meditation, a physical object is used as the object of meditation, being focused upon by the practitioner until an eidetic image of the object forms in the practitioner's mind. In more advanced levels of kasiṇa meditation, only a mental image of the kasiṇa is used as an object of meditation. Unlike the breath, Buddhist tradition indicates that some kasiṇa are not appropriate objects for certain higher levels of meditation, nor for meditation of the vipassana (insight) type.
According to scholars, the Visuddhimagga is one of the extremely rare texts within the enormous literatures of various forms of Jainism, Buddhism, and Hinduism to give explicit details about how spiritual masters were thought to actually manifest supernormal abilities. Abilities such as flying through the air, walking through solid obstructions, diving into the ground, walking on water and so forth are performed by changing one element, such as earth, into another element, such as air. The individual must master kasina meditation before this is possible. Dipa Ma, who trained via the Visuddhimagga, was said to demonstrate these abilities.
Although practice with kasiṇas is associated with the Theravāda tradition, it appears to have been more widely known among various Buddhist schools in India at one time. Asanga makes reference to kasiṇas in the Samāhitabhūmi section of his Yogācārabhūmi.