This Upanishad desires its title from the opening words
Isa-vasya, “God-covered.” The use of Isa (Lord)–a more personal
name of the Supreme Being than Brahman, Atman or Self, the names
usually found in the Upanishads–constitutes one of its
peculiarities. It forms the closing chapter of the Yajur-Veda,
known as Shukla (White).
Oneness of the Soul and God, and the value of both faith and
works as means of ultimate attainment are the leading themes of
this Upanishad. The general teaching of the Upanishads is that
works alone, even the highest, can bring only temporary happiness
and must inevitably bind a man unless through them he gains
knowledge of his real Self. To help him acquire this knowledge
is the aim of this and all Upanishads.
The Upanishads translated by Swami Paramananda
Text from: Project Gutenberg