The Upanisads, or to sit closely:
It refers to the disciple sitting reverentially beside his guru to receive transcendental Vedic wisdom—confidential instructions. Each one is attached to one of the Vedas and give a philosophical purport to some of the Vedas’ teachings (jnana-kanda)—part of sruti.
Establish the Absolute as non-material—generally impersonal and metaphysical. Each addresses a different audience and therefore has a different mood. Each is usually attributed to a specific sage who spoke it, but they are not considered as authors. Presently, there are 108 Upanisads. The Vedanta is considered as the essence of all Upanisads.
Sri Isopanisad (ISO): Isa - controller; Upanisad - to sit closely. As part of the Yajur-Veda, it is one of the 1st Upanisad. Sri Isopanisad clearly reveals the personal feature of God and declare the impersonal feature to be subordinate to Bhagavan.
Some of the themes or principles found in Sri Isopanisad:
The Essence of the Vedas: Srimad-Bhagavatam --> It is the natural commentary on Vedanta by Vyasadeva.
Summary: Introduction—The Importance of Vedic Knowledge:
1.The Vedas are infallible, axiomatic truth as opposed to mundane knowledge.;
2.The aim of the Vedas, as accepted by all, is Krsna, who is beyond the range of our senses and mind;
3.The Veda/Krsna is delivered through pure devotee of Krsna (guru) through the descending process;
4.The essence of the Vedas is Srimad-Bhagavatam;
5.The Upanisads are philosophical sections of the Vedas that point at the Absolute Truth;
6.Sri Isopanisad is important to us because: it is the sruti-sastra part of the Yajur-Veda, which is respected as apauruseya-sabda, divine sound vibration, by all transcendalists, and it defeats impersonalism and supports the personal aspect of God presented in smrti-sastra.