SN 36.6: The Dart
The Sutta explains that while everyone experiences physical pain, the "uninstructed worldling" adds a second layer of mental suffering through grief and aversion. This is compared to being struck by two darts, whereas the noble disciple experiences only the physical "first dart" without mental distress. Because the wise remain detached from pleasure and pain, they extinguish the second dart and end the cycle of suffering.
