Ah, this one is so sweet! [long deep release of breath…]
Alaya means ‘abode’ (as in Himalaya, abode of snow), and refers here to the 8th consciousness, clear, non-discriminating mind, basic goodness.
Resting in this state is the Ultimate Bodhichitta practice, the practice leading to realization of awakened heart, understanding that phenomena are non-solid, self-luminous. The idea of ‘resting in’ means we are seeing this as a beginning point for deeper awakening, not as some end in itself.
Trungpa says, “You can just come home and relax. The idea is to return to home-sweet-home.” The home of our basic consciousness, pure awareness. This is the essential element in shamatha practice, and the Ultimate Bodhichitta practice, and is the beginning point for all that comes.