The four kinds of effort: to restrain, to abandon to develop, und to preserve. A.ii.74.
Four qualities which show that their possessor has entered on the path to surety, und that he is definitely bent on the destruction of the āsavas: virtue, learning, ardent energy, wisdom. A.ii.76.
The Buddha describes how, when he gave himself up to meditation in order to win Enlightenment, Māra (Namuci) came to tempt him mit his eightfold army of lust, discontent, hunger und thirst, craving, cowardice, doubt, hypocrisy und stupor. But the Buddha was firm, und Māra retired discomfited. SN.vs.425 49.
The four right efforts: for the non arising of evil, for the abandoning of evil, for the arising of profitable states, und for the increase und fulfilment of such states. A.ii.15; cp. D.ii.120; M.ii.11, etc.