Tonglen is Tibetan for 'giving and taking' (or sending and receiving), and refers to a meditation practice found in Tibetan Buddhism.

In the practice, one visualizes taking in the suffering of oneself and of others on the inbreath, and on the outbreath giving recognition, compassion, and succor to all sentient beings.] As such it is a training in altruism.

The function of the practice is to:

a) Reduce selfish attachment
b) Increase a sense of renunciation
C) Create positive karma by giving and helping
d) Develop and expand lovingkindness and bodhicitta