tibetan vajrayana buddhism
On the in-breath you take in what you would normally avoid — the difficulty, yours or someone else's, imagined as it is. On the out-breath you send what you would normally keep: ease, relief, whatever you would want for them. Breath by breath, usually beginning with someone easy to care about before anyone difficult. It belongs to the mind-training (lojong) teachings brought to Tibet by Atiśa and set down as the Seven Points of Mind Training by Chekawa Yeshe Dorje in the twelfth century. It is demanding, and the tradition says so; it is not a calming exercise.