Gzer bzhi

Four Nails. These are the four nails which control life-breath srog sdom gzer bzhi according to Yoga Tantra, namely, the nail of unchanging intention mi 'gyur dgongs pa'i gzer the nail of contemplation on the deity ting 'dzin lha'i gzer the nail of mantra which is the nucleus snying po sngags kyi gzer and the nail of activity which is the emanation and absorption of light rays phro 'du phrin las kyi gzer [RY]

four nails [IW]