Īsha Upanishad The Īsha Upanishad also called the Īshāvāsya Upanishad , derives its name from the opening word of the text Īshāvāsya or Īshā . It belongs to the school of the Yajurveda . The Vājasaneya Samhitā consists of 40 chapter of which this Upnishad is the last . It's main purpose is to teach the essential unity of God and the world , being and becoming . It is interested not so much in the Absolute in itself , Parabrahman , as in the Absolute in relation to the world , Parameshvara . It teaches that life in the world and life in the Divine Spirit are not incompatible . The Invocation Prayer : पूर्णं अदः, पूर्णं इदं, पूर्णात् पूर्णम् उदच्यते । पूर्णस्य पूर्णम् आदाय पूर्णं एवावशिष्यते।। That is full , this is full . The full comes out of the full . Taking the full from the full , the full itself remains . । ब्रह्मन् is both transcedent and immanent । । The birth or the creation of the universe does not affect the integrity of the ब्रह्मन् in any Manner । ॐ शान्तिः शान्तिः शान्तिः ईशावास्यम् इदं सर्वं यत् किं च जगत्यां जगत् । तेन त्यक्तेन भुञ्जीथा मा गृधः कस्यस्विद्धनम् ।। १ ।।