"Death's Messengers" (German: Die Boten des Todes) is a German fairy tale collected by the Brothers Grimm, tale number 177.
The young man comes across the beaten-down Death and helps him up.
The grateful Death promises the young man that, though he cannot spare the young man, when the time comes he will send messengers beforehand to warn the young man of his death.
Many years later, the man, no longer young, is caught by surprise when Death comes for him.
But Death points out that he had, in fact, sent messengers: illness, the signs of aging, and sleep.