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Isana Eng wiki page
The name Ishan is also mentioned in Shiva Mahapurana as one of five names of the god (Shiva). Īśāna has its roots in the word "ish", which means the invisible power that governs the universe. The wielder of this power, about this power itself, is "Īśāna". It is synonymous with Ishwar, which means "The Lord". In Hindu Scriptures, this is a name given to Shiva. As per Hindu scriptures Shiva has five heads, each denoting one of the five tattvas (elements) namely Fire, Earth, Air, Water, and Ether (also called as Sky-element or Akash-tattva in sanskrit) that make up the universe.
Īśāna signifies the subtle and ethereal form of Shiva that represents transcendental knowledge. This dimension is reinforced by which says that Ishan-Disha (north-eastern direction) represents Prosperity and Knowledge. It is also considered to be the name of the god of Vastu Śāstra. the Brahman splits into male (Parashiva) and female (Parasakti) and manifests as the universe. The Parashiva has five aspects:
Sadyojata - west aspect that propagates manifest Brahman-associated with Brahma - represents earth.
Vamadeva - north aspect that sustains manifest Brahman - associated with Vishnu - represents water.
Aghora - south aspect that rejuvenates manifest Brahman - associated with Rudra - represents fire.
Tatpurusha - east aspects Rishi, Muni, Jnani, yogi - represents air.
Isana - an internal aspect that conceals - associated with all that exists - represents akasha.