Patanjali Yoga sutra, the richest form of yogic text has given the sutra on meditation ‘Dhyana’. The sutra is the second sutra of vibhuti paada (3rd chapter) of patanjali yoga sutra.
तत्र प्रत्ययैकतानता ध्यानम् |
tatra pratyayaikatānatā dhyānam |
The sutra defines the meditation here, it says ‘an unbroken, continuous flow of knowledge of the object on which one is concentrating is called meditation or dhyana‘. When mind stays in the state of dharana for sometime without any break that itself called Dhyana.
Dhyana or meditation is being witness of ‘self is meditating’ on the object. So being aware of the object and being aware of self is meditating without any interruption is Meditation. One can meditate on any object, sound, smell or anything and while meditating on the object he is aware that he is meditating.
Dhayna or meditation is the seventh limb of the ashtanga yoga compiled by Maharishi Patanjali. Ashtanga yoga is the tool to reach to the goal of yoga. Last and the eighth limb is the fruit of Dhyana and the ultimate goal i.e. Samadhi – the realization.