Not as pithy, but this is (probably) the original source: https://www.accesstoinsight.org/tipitaka/sn/sn36/sn36.006.than.html https://www.accesstoinsight.org/ti

Not as pithy, but this is (probably) the original source: https://www.accesstoinsight.org/tipitaka/sn/sn36/sn36.006.than.html https://www.accesstoinsight.org/tipitaka/sn/sn36/sn36.006.th... It's often phrased in terms of the "first arrow" (pain) and the "second arrow" (suffering in reaction to the pain): the second arrow is optional and self-inflicted.