To keep a vajra to remind us of great bliss.
There are two types of vajra: outer and inner. To remind us that the development of the inner vajra of great bliss is our main practice we keep an outer vajra (a metal ritual object, or at least a picture of one). The vajra also symbolizes the attainment of the five omniscient wisdoms of the five Buddha families. Realizing this we should regard it as an object of the field of merit and make offerings to it.
The point of this vow is not to go to the Dharma shop in our local center, buy a vajra and put it on our shrine. While of course we need to do so, the real point is to remember the vajra of great bliss all of the time. The actual physical vajra is merely an external representation to help us remember.
People sometimes get very confused about great bliss. Because our only basis for the experience of bliss is sexual orgasm, most of society equates Tantric practice with strange sexual practices. Open any newspaper, and you can find a menu of options to choose from in terms of “Tantra classes” and the only requirement for attending them is loose fitting pants. Needless to say, this is not what is meant by qualified Tantric practice.
The essential point of tantra is to generate the most powerful, subtle mind possible, and then to use that mind to mediate on the most powerful, subtle object of meditation possible. If we do this, we will attain enlightenment the most quickly possible. Our mind has three levels to it, gross, subtle and very subtle. Roughly speaking, our gross mind refers to the level of mind we normally have while we are awake; our subtle mind refers to the level of mind we normally have when we are dreaming; and our very subtle mind refers to the level of mind we normally have at the last moment of death, when all the appearances of this world completely re-absorb. All of our gross minds originate from our subtle minds, and all of our subtle minds originate from our very subtle mind. Our very subtle mind, our root mind, and the mind of great bliss are synonymous.
The fundamental mechanism by which Dharma works is by placing the wisdom of Dharma deeper within our mind than the delusions we suffer from. If we can do so, we effectively uproot and remove that particular delusion from our mind. To use arbitrary numbers to illustrate the point, if we have a delusion which reaches down to level 4 in our mind, and we only place the Dharma down to level 3, then the Dharma will cut off the tops of the delusion but it won’t remove the roots of the delusion, and it is just a question of time before the delusion grows back. It is like pulling weeds, but not doing so by their roots. If instead we place the Dharma down to level 5 within our mind, then the Dharma will completely uproot and remove that particular delusion within our mind. Meditation, quite simply, is a method for planting the Dharma more deeply within our mind. The more powerful our meditating mind, the deeper we plant the Dharma. The deepest level of mind of all is our very subtle mind. If we can place the Dharma at that level of our mind, then it literally gets underneath all of our delusions, and indeed their past karmic imprints, and uproots all of them directly and simultaneously. The most powerful mind is the very subtle mind of great bliss, and the most powerful object is ultimate truth emptiness. But we do not seek to just realize emptiness with our very subtle mind, we seek to realize all of the lamrim meditations with this mind.
How do we actually generate the mind of great bliss? To answer this, we must first know what is a qualified mind of great bliss. Sexual bliss is an agitated, grasping mind. Great bliss is completely different. The best way of understanding it is take a feeling of inner peace that comes from your lamrim practice, then take that feeling of peace to its ultimate extreme – a mind so peaceful, it feels blissful. It is a fully satiated mind that lacks and wants for nothing. It is a feeling of sublime calm that radiates from the inside out, melting everything into a supreme contented joy. The primary means by which we generate this mind is, through the force of meditation and assisted by blessings, we cause our inner winds to gather, dissolve and absorb into our central channel, in particular at our heart. All of our tantric meditations of generation and completion stage are, in fact, methods for gathering our inner winds (and removing the obstructions to them gathering). The more they gather, the more our mind becomes peaceful, and the more peaceful it becomes, the more blissful it becomes. Pursuing this experience day and night is the real meaning of the vow.