Īśā Upanishad - takeaways
The Upanishad starts by establishing the ownership of this universe as that of the Lord, i.e. Īśā. When the universe belongs to the Lord, one must find satisfaction with whatever one gets and must not envy other's wealth.
Just because the universe belongs to the lord, does not advocate inaction. One must engage in proactive action for the welfare of the world and must aspire to live as long as possible. If one does not engage in action towards the welfare of the universe that is authentic to their essence, then they become destroyers of their own essence, and thus enter the world of ignorance.
The individual who comprehends that all beings reside within the Supreme Being, takes refuge in Him alone, and perceives His presence in every entity is not subject to delusion.
Vidya, that which comes to light, refers to knowledge about what exists. It's the affirmation or assertive knowledge. Avidyā, that which does not come to light, refers to knowledge about what does not exist. It's the knowledge derived from negation or denial. It is important to note, epistemologically, Upanishad is opening a new dimension and meaning for 'Avidya' than the more generally accepted meaning, which is ignorance. One should not possess 'Avidya' but should understand 'Avidya'.
The word 'sambhava', i.e. becoming or coming into existence, and 'asambhūta', i.e. un-becoming, to dissolve, to go out of existence, are profound metaphysical concepts. The process of becoming and un-becoming are identified as two distinct aspects of reality and understanding both the aspect is necessary.
The Upanishad ends with an ardent cry of the devotee, asking the lord to remember his deeds and to bestow His grace.
