As I've only seen this method of actively practicing kyerim meditation on the Four Thoughts in Kalu Rinpoche's book, and believe that it's Lama Norlha who penned these words in the appendices quoting the 1st Karma Chagme, I have put this post in the Kagyu sub-forum. However I can't see why this method wouldn't be valid for students of any Vajrayana lineage, so please feel free to mention it beyond here.
I'm admittedly unsure if there is an actually sadhana where this visualization practice is featured, and as such cannot comment on whether or not a transmission is required. If anyone knows, I would love to have clarity on this point.
pp. 146-148 wrote:Meditation Practice
To fulfill what it means to have found a Precious Human Birth with its eight opportunities and ten resources it is essential to be aware of how rare the inconceivable power and ability we now have for practicing Dharma really is. If we don't make use of this opportunity we will soon lose it, and it will be difficult to find again.
All human beings can be classified as lesser, middling, or greater persons with regard to basic motivation and ability. Lesser persons are those who practice virtue for the sake of improving their own situation during this lifetime in order to be happy and comfortable. The middling types are those who understand that this life is impermanent and full of suffering, and perform virtuous actions with the idea of achieving peace in the next lifetime. People of this second type have an understanding of cause and effect and know that through negative behavior their next lives will be negative, while positive behavior will yield positive fruits later. The third, greater type of person also understands the law of cause and effect, but in addition appreciates the fact that all sentient beings have been our parents. Such a being will not try to win peace for himself or herself, but has the idea that it is necessary to purify karma and emotional afflictions so as to achieve perfect Buddhahood for the benefit of all beings.
With the precious human body we are able to perform virtuous actions, cast off negative actions, practice the path of the Bodhisattva to attain Buddhahood as Milarepa did, and unfailingly accomplish in this life the benefit of all sentient beings. Therefore this precious human body that we've obtained is far more powerful than that of the beings of the six realms such as the gods, nagas, and so on. When meditating on the difficulty of attaining a precious human existence, however, you must realize that its fruits will not necessarily appear in this lifetime, but rather may not ripen until future lifetimes.
If the body were completely permanent and unchanging, any activity would be acceptable. Because the body really is impermanent, it is important to practice Dharma immediately. We cannot predict what kind of birth we will take in our next life; we cannot assure ourselves that our next life will be happy or that we will avoid suffering. It is therefore important for us to think about the great sufferings of the three lower realms: the hell and hungry ghost realms that we cannot see, and the animal realm of which we see only a part, and not even the part with the greatest suffering. When we consider very carefully the tremendous suffering of the lower realms, we righly become sad and frightened.
On this topic there is a special meditation devised by Karma Chamay [chags med], a great lama from eastern Tibet. He lived in the seventeenth century, during the time of the ninth and tenth Karmapas. I have received this teaching myself, and find it an especially effective method of meditation.
Begin by visualizing a high mountain. Around that mountain are regions full of beings of the six realms of samsara. Think about all the different kinds of karma that each of those sentient beings has, and all the various sufferings that each of them is experiencing. Reflect on them and visualize them very clearly. Then look at yourself: you have a sound body, can rely on Lamas, practice Dharma, and enter any path you choose. Reflect joyfully on the favorable situation you have attained and understand it to be the fruit of accumulated merit of virtuous actions in previous lives. Consider that all those sentient beings around the base of the mountain are experiencing the results of unvirtuous actions and are now suffering greatly. Then realize that your situation is also difficult -- you too will fall into those realms of great suffering. At this point the thought comes to you that you must find some ultimate means of freeing yourself from this cycle of suffering.
Above and before you in the sky visualize your lama as any yidam in the Buddhadharma in whom you have great faith. Meditate on him. For this particular practice it is especially effective to visualize the Lama as Chenrezi, since this deity is known for his love and compassion. Imagine him as the essence of all Buddhas. Then hear the Lama say to you: "You have obtained a precious human body and are able to hear, contemplate, and practice the perfect Dharma. But if you don't accomplish virtuous action and abandon evil, no good will come. If you don't obtain a precious human body in your next life you will experience great suffering."
Meditate on the suffering you will experience if you fall into each of the lower realms. By renouncing and accepting, your human life will become meaningfully fulfilled. Also think about the fact that all sentient beings in the unending cycle of rebirth have at one time or another been your mother and very kind to you; therefore, arouse great compassion and feeling for their suffering. Resolve with determination that you will quickly establish each of them without exception in a Buddha realm.
Next, visualize that from Chenrezi's heart come rays of light. The rays touch you, purifying all the sins and obscurations of your body, speech, and mind. You are instantaneously reborn in Dewachen [bde ba can], the Pure Realm of Great Bliss. Then, through the power and ability you thus obtain, light rays emanate out from your heart and touch all sentient beings, purifying their suffering, sins, and obscurations; they too are reborn in the Pure Realm and become fortunate ones, completely enlightened. At this point you can visualize yourself and all others as being Chenrezi.