The Īśa Upaniṣad (ईशोपनिषद्) — also known as Īśāvāsya from its opening word — is the shortest of the principal Upanishads and the only one embedded in the Samhita of its Veda (it forms chapter 40 of the Vājasaneyi Saṃhitā of the Shukla Yajurveda). In eighteen verses it presents a strikingly complete vision of the Vedantic project, and for that reason it is traditionally read first in the standard sequence of the daśopaniṣad — the ten major Upanishads.
Opening Mahāvākya
ईशा वास्यमिदं सर्वं यत्किञ्च जगत्यां जगत् । तेन त्यक्तेन भुञ्जीथा मा गृधः कस्यस्विद्धनम् ॥
īśā vāsyam idaṃ sarvaṃ yat kiñca jagatyāṃ jagat
tena tyaktena bhuñjīthā mā gṛdhaḥ kasyasvid dhanam
"All this — whatever moves in this moving world — is enveloped by the Lord. Therefore enjoy through renunciation; do not covet anyone's wealth."
The verse fuses theology and ethics. Because the world is divine, it is not a thing to be possessed; the proper relation is enjoyment-through-relinquishment. Gandhi singled out this verse as the seed of his own moral philosophy.
Action with Knowledge
Verse 2 takes up an objection: if the world is divine and the proper attitude is renunciation, must one withdraw from action? The Upanishad answers:
कुर्वन्नेवेह कर्माणि जिजीविषेच्छतं समाः ।
kurvann eveha karmāṇi jijīviṣec chataṃ samāḥ "Performing works alone here, one should wish to live a hundred years."
Action is not to be abandoned. What changes is the attitude in action: the worker does not cling to the fruits of action and does not act for personal gain. This formulation will be expanded into the doctrine of niṣkāma karma in the Bhagavad Gita.
The Vision of Unity
The central philosophical heart of the occupies verses 4 through 8. The ātman is described as paradoxical — moving and unmoving, far and near, within all things and beyond all things. Verse 6, often counted as the Isha's contribution to the mahāvākya tradition:
यस्तु सर्वाणि भूतान्यात्मन्येवानुपश्यति । सर्वभूतेषु चात्मानं ततो न विजुगुप्सते ॥
yas tu sarvāṇi bhūtāny ātmany evānupaśyati
sarvabhūteṣu cātmānaṃ tato na vijugupsate
"One who sees all beings within the Self, and the Self within all beings, has no aversion thereafter."
This is the Upanishadic ground of the Hindu tradition of non-othering — the perception that becomes, in practice, ahiṃsā.
The Knot of Knowledge and Ignorance
The most strikingly dialectical passage is verses 9–11:
अन्धं तमः प्रविशन्ति येऽविद्यामुपासते । ततो भूय इव ते तमो य उ विद्यायां रताः ॥
andhaṃ tamaḥ praviśanti ye'vidyām upāsate
tato bhūya iva te tamo ya u vidyāyāṃ ratāḥ
"Into blind darkness enter those who worship ignorance; into still greater darkness those devoted to knowledge alone."
The Upanishad rejects both options. True wisdom requires the conjoint practice of vidyā (knowledge of the imperishable) and avidyā (in the sense of ritual and action in the world): "by avidyā one crosses death, by vidyā one attains immortality." The same paradoxical structure is then repeated for sambhūti (becoming) and vināśa (non-becoming, or the unmanifest).
This is not casual rhetoric. The verse stages a deliberate refusal of two opposed temptations: pure ritualism without inquiry, and pure intellectualism without practice. The wise person walks the path that holds both.
The Closing Prayer
The Upanishad ends with three intensely poetic verses addressed to the Sun and Agni at the moment of death.
हिरण्मयेन पात्रेण सत्यस्यापिहितं मुखम् ।
hiraṇmayena pātreṇa satyasyāpihitaṃ mukham
"The face of truth is concealed by a golden disk; O Pūṣan, uncover it, that I, whose dharma is truth, may see."
The petitioner asks the Sun to withdraw the dazzling cover; asks the dying body to dissolve into the elements (vāyur anilam amṛtam); asks Agni to lead by the good path and to remove the crookedness of error. The closing word, svāhā, is the ritual exclamation of offering — the Upanishad ends as a fire-offering of the self.
Commentarial Reception
All major Vedantic ācāryas — Śaṅkara, Rāmānuja, Madhva — wrote commentaries on the , and their readings diverge characteristically. Shankara reads the dialectic of verses 9–11 as resolved into pure jñāna; Ramanuja reads it as enjoining bhakti united with action; Madhva reads it as the proper subordination of human effort to the Lord. The Upanishad's compression has been generous to commentators. For most readers, however, its lasting force is the first verse — the world enveloped by the Lord — and the inseparable command that follows it: do not covet what is, in the end, never yours to possess.