The third Jamgn Kongtrul (1954-1992), Buddhist monk and teacher, was one of the heads of the Kagy order of Tibetan Buddhism.
In this book he provides a commentary on the vajra song (vajra doha) of the first Jamgn Kongtrul ("the Great"), sung upon realizing mahamudra. Masters have often expressed their insights in the form of these songs, whose meaning is considered indestructable and unchanging. This particular doha is part of the Kagy Gurtso, or "Ocean of Kagy Songs."
From the foreword: "Using the vajra song as a starting point, Jamgn Kongtrul Rinpoche presents both an overview of mahamudra, the heart of the Kagyu teachings, and some very practical advice for those who wish to tread upon the mahamudra path.
From the commentary: "What is meant by mahamudra? Mahamudra consists basically of three aspects: ground, path, and view mahamudra.
"Ground mahamudra is the unity of relative truth and ultimate truth. It is freedom from both the two extremes of eternalism and nihilism."
"Path mahamudra is the union of skillful means and wisdom. (...) one accomplishes the two types of accumulations, merit and wisdom. In essence, the path consists in uniting these two accumulations."
"Fruition mahamudra is freedom from the extremes of samsara and nirvana. (...) Fruition mahamudra is the realization of the unity of dharmakaya and the form kayas."
"In other words, mahamudra is recognizing the nature of one's own mind."
The book also contains a moving biography of the third Jamgon Kongtrul by Bokar Rinpoche