Khenpo Sherab Sangpo offered teachings on the Signs that the Common Preliminary Practices Have Penetrated the Mind by Nyala Pema Dündul.
Nyala Pema Dündul was a famous treasure revealer from Tibet in the 19th century and was the last among many yogis from Katok who successfully attained the rainbow body. This teaching contains an explanation on the signs that the common preliminary practices have penetrated the mind, including the four thoughts that change the mind, the inner preliminary practices, and one of the most profound Dzogchen teachings.