Kasiṇa

A kasiṇa is a simple meditation object — such as a disk of earth-colored clay, a bowl of water, a flame, or a patch of color — that you gaze at steadily to gather and calm the mind. In the early Buddhist tradition it's one of the classic supports for developing deep concentration (samādhi): you look at the object until its image grows clear in your mind, then rest your attention on that inner image to settle into stillness and the meditative absorptions (jhāna). It works much like quietly watching a candle flame — one gentle, unchanging thing for the restless mind to rest upon.