The Long Āgama Sūtra 2.32

2.32

佛告比丘：「復有七法，則法增長，無有損耗。何謂為七法？一者觀身不淨，二者觀食不淨，三者不樂世間，四者常念死想，五者起無常想，六者無常苦想，七者苦無我想。如是七法，則法增長，無有損耗。」

The Buddha told the monks, “There’s another seven principles that will make the teaching grow and not diminish. What are the seven? First, observe the impurities of the body. Second, observe the impurities of food. Third, don’t be happy with the world. Fourth, always be mindful of the idea of death. Fifth, [be mindful of] the idea that what arises is impermanent. Sixth, [be mindful of] the idea that impermanence is painful. Seventh, [be mindful of] the idea that what’s painful is not self. Thus, the teaching will grow and not diminish with these seven principles.”