What the Upanishads say about letting go
A note on the theme before the concepts. The famous teaching about giving up the fruits of action belongs to the Bhagavad Gita, not to the Upanishads. What the Upanishads have is older and looser: a verse about acting as an offering, and a vocabulary for how a grip loosens once you have seen what lasts. Two of the eight words below come from a later Vedantic manual that the library cites by name, the Vivekachudamani, and that is said where it applies.
Karma Yoga in the Upanishads
The Isha Upanishad's opening frames action as an offering, performed without attachment. The work stays; the claim on what it produces does not.
Isha Upanishad 1-2
Maya - The Cosmic Illusion
Maya is the name for the way one reality appears as many, concealing as it displays. It is a diagnosis of why things look more solid than they are.
Shvetashvatara Upanishad 4.10
Viveka - Discrimination
Viveka is telling the lasting from the passing. The later manuals put it first, because letting go without it is just loss.
Vivekachudamani
Vairagya - Dispassion
Dispassion, in this account, is not forced. It is what happens to attachment once the temporariness of the thing has actually been seen.
Vedantic Teachings
Pratyahara - Withdrawal of Senses
The Katha describes the five senses and the mind coming to rest, with the intellect no longer stirring. It is a description of stillness rather than a method for producing it.
Katha Upanishad 2.3.10
All is Food
All beings are born from food, live by food and return to it. It is difficult to feel like an owner of anything inside that sentence.
Taittiriya Upanishad 2.2.1
Beyond Virtue and Vice
The Taittiriya says the one who knows is no longer troubled by why did I not do good and why did I do wrong. It is presented as the end of self-accounting, not as permission.
Taittiriya Upanishad 2.9
The Tenth Man
Ten men cross a river and one counts nine, leaving himself out. The library gives this as a traditional teaching story rather than a scripture verse, and it makes the point about searching for what was never missing.
Advaita Teaching Stories
Letting go, in these texts, is closer to a consequence than to an act. See what passes as passing, and the grip loosens without having to be prised open. That is a slower claim than most advice makes, and it puts the effort where the tradition thinks it belongs: on looking, not on trying.