坐禪三昧經 1.54

1.54

"Just as an arhat instructed disciples vexed by various thoughts, saying: 'Why do you not know weariness of the world and enter the path? Why do you give rise to such thoughts? Some die before they are even born; some die at the very moment of birth; some die during nursing; some die when weaned; some die in childhood; some die in their prime; some die in old age. In all times, the realm of death intervenes. It is like tree blossoms: some fall while in blossom, some fall when bearing fruit, and some fall while still unripe. Therefore, you should know that you must strive with diligent vīrya to seek the path of security; living together with a bandit of great strength cannot be trusted. This bandit is like a tiger skillfully concealing its body; thus this bandit of death constantly seeks to kill people.'