This Upanishad belongs to the Vaajaseneyi Samhita of the Shukla (White) Yajur Veda and forms the last chapter of this Samhita. It is also called a Mantropanishad, as it forms a part of a Samhitâ.
Central ThemeThe IshAvAsya has the central theme of extolling the sarva-vyaapakatva (all pervasiveness) and sarva-niyaamakatva (all regulating) nature of the Supreme Lord. These are mentioned in the very first expression used in the Upanishad -- IshAvAsyam, which not only conveys His all-pervasiveness but also that He controls all. The next phrase used -- yat.h kincha jagatyAM jagat.h -- makes this more clear. This phrase tells us that all the things in the world are in Prakrti and dependent upon it. Prakrti itself is dependent upon Him. Hence the Lord alone is independent and all others are dependent upon Him. This point is stressed in verses 6 and 7, where in the Lord's presence and control in all things is brought out. In order to bring home these two characteristics of the Lord, the Upanishad gives a full exposition of the concepts. Two requirements for a seeker to know the Lord are also mentioned -- vairaagya, brought out by the phrase "tena tyaktena bhunjiitha" -- accept with equanimity what ever is given by Him, and vihita karmanushhThaana, brought out by kurvanneveha karmaaNi.
Nature of GodThe Unique nature of the Supreme is explained in the verses anejadekam ...," etc. (verses 4 to 8). He is everywhere. He is near and yet also far away. He is within and without. He moves but does not move. These apparently contradictory attributes reveal his achintya shakti -- unthinkable ability. He has no praak.rta body, either subtle or gross. He is eternal, free from defects. He is a "sarvaj~na" (knows everything). He regulates all. He has truly created this real world.
Vidya & AvidyaThose who do not know correctly the nature of the Lord will go down to the worlds of misery. One has to have the right knowledge (vidyA) and not only avoid wrong knowledge (avidyA), but should also condemn and refute it. Not condemning knowledge known to be wrong is more sinful than not having right knowledge. Both acquiring vidyA and condemning avidyA serve their respective purposes in leading to Liberation. Similarly, it is also necessary to know that He is a Creator and Destroyer. Knowing Him as Creator only is sinful.
PrayerAt its end, the Upanishad contains a beautiful prayer -- hiraNmayena patreNa -- wherein the devotee appeals to the Supreme to reveal His nature to him. A number of pratiika-s (symbols) are also mentioned -- Suurya maNDala, Yama, Prajaapati, etc. Each devotee is expected to meditate upon Lord in a pratiika suitable to him. The passage yo asau asau purushhaH teaches the most important doctrine that the Supreme Lord present in all the pratiika-s and in the devotee himself is one and the same. Both from the context and the words used in the prayer, it is apparent that no Identity between the devotee and Lord is intended. The word ahaM is used in the sense of asmadantaryAmi -- the Lord immanent in my heart. The second asau refers also to Mukhya PraaNa -- it means Mukhya PraaNa, in whom Lord is specially present. The words ahaM and asmi refer to the Lord with special meanings. ahaM means aheyaM -- that which is never capable of being separated, while asmi means being always present and to be known. Upanishads use a code language to convey special meanings. Thus, both by way of normal construction of language and the special construction, the phrase yo asau asau describes His everywhere, which is the main theme of the Upanishad. Finally the devotee appeals to the Deity to remove the contamination of bandhaka karma (results of past deeds which bind him to the world) and to provide him with svarUpa j~nAna (innate knowledge) to reveal his true nature. This is one of the best prayers found in the Upanishads, deep in its spiritual content and exciting in its poetic appeal.This Upanishad has three special features.
- The Referent described here is fully Theistic.
- Reality of the world is expressly mentioned.
- An active life with performance of prescribed Karmas is given importance. Escape from one's duty is not accepted.