From the Viddui (confession);

You know the secrets of the universe,
And the hidden mysteries of all the living.
You probe all the innermost chambers,
and test thoughts and emotions.

Nothing is hidden from You
And nothing is concealed from Your eyes.

And so may it be Your will
Lord our God,
And God of our fathers,
That You forgive us for all our errors,
And you pardon us for all our iniquities,
And You atone for us
For all our willful sins.

From the Avodah service of the High Priest

(When the Temple stood, the centerpiece of Yom Kippur was the special service performed almost exclusively by the High Priest. Many of its components, including the choice of goat to be dispatched and pushed of a desolate cliff, were unique to Yom Kippur. This Avodah service effected the entire nation who waited with abated breath for a sign that atonement was achieved and that the High Priest would emerge safely from the Holy of Holies in the Temple, at the end of an arduous day.)

A piyyut of unknown authorship:

True! - How majestic was the High Priest
As he left the Holy of Holies
In peace and without injury.

Like the heavenly canopy
Stretched over those who dwell above;
Like lightning bolts
Emanating from the radiance of the
heavenly beings...;
Like the sight of sunlight upon the earth;
Like the garden's rose among the thorns;
Like the appearance of constellations from the south.

[Such] was the appearance of the [High] Priest.