Tonglen (also spelled Tong Len) is a Tibetan Buddhist meditation practice that focuses on cultivating compassion and altruism through a process of "giving and taking" (literally, tong means "giving," and len means "taking").
Tonglen practice, also known as "taking and sending" reverses our logic of avoiding suffering and seeking pleasure. In tonglen practice we visualises taking in the pain of others with-even in the breath and sending out whatever will benefit to them, on the out breath.
Tonglen is a mind-training (Lojong) practice in which the practitioner:
Inhales the suffering of others,
Exhales relief, compassion, and healing to them.
It reverses the ordinary habit of avoiding suffering and seeking pleasure for oneself. Instead, the practice opens the heart by connecting deeply with others’ pain and cultivating the wish to alleviate it.
Cultivates compassion and empathy
Dismantles ego-clinging and self-centeredness
Deepens awareness of interconnectedness
Builds emotional resilience in the face of suffering
Tonglen is associated with the Lojong teachings, particularly from teachers like:
Geshe Chekawa (author of Seven Points of Mind Training)
Pema Chödrön (modern teacher who popularized it in the West),
Also read "Lungta" wind horse or other ancient meditation practices, such as raising energy for driving more deeper.