Tonglen is a meditation practice that is connected to the breath. It is said to have been a secret practice of Atisha, practised only with his disciples. It begins with visualising a person, group, or situation where help is needed. On the in-breath all pain and dissatisfaction is received and absorbed. On the out-breath limitless benefit and help is given.
This is a practice of developing awakening intent – the wish to benefit others. The breath is a natural rhythm of being a human being – to be alive is to breathe. To use a fundamental requirement of life as a means of awakening is skilful practice. Tonglen engages this natural rhythm. Breathing in is receiving. Breathing out is giving.
Battlecry of Freedom by Ngakma Nor’dzin, Aro Books worldwide, 2019, ISBN 978-1-898185-46-8, Part II - the slogans, p59