Soham or Sohum (सो ऽहम् so'ham[1]) is a Hindu mantra, literally meaning "That (is) I" in Sanskrit, implying "I am that".
[2][3] The term is found in Vedic literature, and is a phrase that identifies "One with the universe or the ultimate one reality".
[7] Some examples include: Upanishads Tantras Stotras Adi Shankara's[32] Vakya Vritti[33] subsequent works in the Nath tradition foundational for Hatha yoga.
[57][58][59][60][61] The teaching of Ham on inhalation and sa on exhalation is allegedly alluded to in a text of Kaśmir Śaivism, the Vijnana Bhairava: Air is exhaled with the sound SA and inhaled with the sound HAM.
Then reciting of the mantra HAMSA is continuous[62]However, this verse 155b is not found in the Vijnana Bhairava first published in 1918 in the Kashmir Series of Text and Studies[63] but is quoted from a commentary by the Abhinavagupta disciple Kṣemarāja[64] in his Shiva Sutra Vimarshini (commentary on the Shiva Sutras)[63] in later editions of Vijnana Bhairava.