The Mahima Siddhi Mantra is a sacred invocation associated with the yogic power (siddhi) of mahima, the ability to become infinitely large and expand one's consciousness to encompass all existence. This siddhi is enumerated among the eight classical yogic powers (ashta siddhi) described in texts such as the Yoga Sutras of Patanjali (Vibhuti Pada, sutra 45: 'tato 'ṇimādi prādurbhāvaḥ kāya-sampat tad-dharmānabhighātaś ca'), where it is listed as one of the animadi siddhis, the powers of becoming small (anima), light (laghima), large (mahima), etc. The mantra is traditionally chanted to attain this power of expansion, which is said to allow the yogi to assume a cosmic form and pervade all space. In the Puranas, particularly the Shiva Purana and Vishnu Purana, mahima siddhi is often attributed to Lord Shiva and Lord Vishnu, who are known for their cosmic forms (Virat Swarupa). The beej-akshara (seed syllable) 'Mam' (मम्) is sometimes used as a bija for mahima, representing the expansive nature of the universe. The mantra 'Om Mahimne Namah' is a common form, where 'Mahimne' is the dative case of 'mahiman' meaning greatness or vastness. According to the Mantra Mahodadhi (a tantric compendium), such siddhi mantras should be chanted with proper diksha (initiation) and under the guidance of a guru, as they bestow immense power that must be handled with spiritual maturity. The recommended chanting count is 108 repetitions per session, ideally during the brahma muhurta (pre-dawn hours) or on new moon nights (amavasya) when the energy of expansion is most accessible. The practitioner should sit in a stable asana, facing east or north, and visualize the deity (Shiva or Vishnu) in their cosmic form, expanding beyond the limits of the body. Cautions include the necessity of purity of intention; the mantra should not be used for egoistic purposes, as the power of mahima is meant for spiritual realization, not worldly display. The Yoga Sutras (Vibhuti Pada, sutra 46: 'tato 'ṇimādi prādurbhāvaḥ kāya-sampat tad-dharmānabhighātaś ca') also warn that attachment to siddhis can become an obstacle to samadhi. Thus, the Mahima Siddhi Mantra is a tool for expanding consciousness and realizing the oneness of the individual self with the cosmic self, as taught in the Upanishads.
The power to become infinitely large, the expansion of consciousness.