This is a scriptural commentary of Lahiri Mahasaya on the following scriptures in the Light of Kriya :

The Bhagavad Gita
The Omkar Gita
The Upanishads
Kabir's Dohe(Couplets)

The Bhagavad Gita

Bisad Yoga : Arjuna's (Seeker's) Melancholy
Sankhya Yoga : Knowledge of the Self
Karma Yoga : Action
Jnan Yoga : Knowledge and Wisdom
Karma-Sanyas Yoga : Action and Renunciation
Avyas Yoga : Practice
Jnan-Bijnan Yoga : Knowledge and Realization
Akshara-Brahma Yoga : The Eternal Self
Raja Vidya Raja Gujya Yoga : The Supreme Science and The Supreme Secret
Bibhuti Yoga : The Divine Glories
Biswarupa Darsan Yoga : The Universal Form of The Self
Bhakti Yoga : Devotion
Kshetra and Kshetrajna : The Prakriti-Purusha Yoga
Gunatraya Bibhag Yoga : Threefold Qualities
Purushottam Yoga : The Supreme Person
Daibasura Sampad Bibhag Yoga : The Divine and Demoniacal Properties
Shraddhatraya Bibhag Yoga : The Threefold Respect
Moksha Yoga : Liberation

The Omkar Gita

This physical body is the form of Omkar.

Please note that the Guru here means the Kutastha, i.e., the place between the eyebrows, also known as The Third Eye.

When the air, or breath, of the navel and dorsal are dissolved in the sky of Kutashtha, this is the third part of Omkar, or Pranava.

Every word uttered by a Yogi has a special meaning that is totally unintelligible to even the highly intellectual people. This book is written in such a way that everyone can follow it up while trading the path of Kriya. People think that they are very intelligent, but if they try to understand very seriously, they realize perfectly that nothing is happening according to their intellect.

Only those whose breath is not blowing in the left or right nostril are intelligent in this world.

Kutastha is Omkar in the form of inner Light due to the uniting of Akara, Ukara and Makara into one.

The Upanishads

If we scan the word Upanisad, we see that Upa means sitting and nisad means near. Thus, the very word Upanisad specifies personal relationship: the Guru-param-para, Master to Disciple learning from the living lips of a Guru.

When breathing is faster, then in one day and one night respiration can flow up to 113,680 times. Normally during the same time, the figure is 21,600 times.
During a day and night, if respiration is faster than usual, the breath can flow in and out 113,680 times. Normally, in the course of a day and night, there are 21,600 breaths.
This figure is reduced by Kriya practice to 2,000 times. So, breathing 1,000 times in the day and 1,000 times in the night, in a normal course, provides greater Tranquility to a Yogi.

One of his breaths takes about 44 seconds.

Such a Yogi is matured in Kriya practice.

Kabir's Dohe(Couplets)

This is a scriptural commentary of Lahiri Mahasaya on The Mystical Songs (Couplets-Dohe) of Kabir, In The Light Of Kriya.

To keep the energy in the head and throat and in Kutastha for a long time is state of Kabir.
Atma is the Guru in this physical body, and the supreme Person (Purushottama) resides in Kutastha.