Hagakure, The Book of the Samurai (meaning 'Hidden Leaves')
Translated by William Scott Wilson
Meditation on inevitable death should be performed daily. Every day, when one’s body and mind are at peace, one should meditate upon being ripped apart by arrows, rifles, spears, and swords, being carried away by surging waves, being thrown into the midst of a great fire, being struck by lightning, being shaken to death by a great earthquake, falling from thousand-foot cliffs, dying of disease or committing seppuku at the death of one’s master. And every day, without fail, one should consider himself as dead.
There is a saying of the elder's that goes, "step from under the eaves and you're a dead man. Leave the gate and the enemy is waiting." It is not a matter of being careful. It is to consider oneself dead beforehand.p.164
I found this in an old notebook of mine, which had a selection of quotes showing that I've always been a cataloguer at heart. This must date from around 2004.