This is a weekly class from Deer Park Monastery on the topic "The 40 Tenets of Plum Village" and it is based on a book called Plum Village Looks at Vulture's Peak written by Thich Nhat Hanh. The book describes the essential characteristics of Plum Village practice and teachings.
For an English translation of the tenets themselves, follow this link.
In this class, Brother Phap Luu discusses the 30th tenet: "A dharma is not a thing, an entity, but a process, an event and above all an object of mind."