Patient Endurance of all Dharmas
Patient endurance of all dharmas is regarding all phenomena, including our own experiences of pleasure and pain, as having the nature of emptiness--that all driarmas lack independent self. This kind of patience encompasses all favorable and unfavorable conditions, and embraces the two previous patience practices.
Contemplating Emptiness
When we practice the three kinds of patience, we are actually contemplating emptiness. In principle, the three practices progress from enduring those who wish to harm us, to enduring difficulties in our body and in the environment, to enduring the emptiness of dharmas. In a sense, the third kind of patience is the easiest, since you can practice it any time and anywhere by contemplating the emptiness of all dharmas. As a result you can also perfect the previous two patience practices. When we contemplate the impermanence of all our experiences--whether painful, pleasurable, or neutral--we gain an insight into selflessness. We can understand the meaning of emptiness through this insight of selflessness, and directly engage the Dharma.