Trường Bộ Kinh (Digha Nikaya) 2:179
SUJATOYo kho, bhikkhave, aññataraññatarena byasanena samannāgatassa aññataraññatarena dukkhadhammena phuṭṭhassa soko socanā socitattaṁ antosoko antoparisoko,
The sorrow, sorrowing, state of sorrow, inner sorrow, inner deep sorrow in someone who has undergone misfortune, who has experienced suffering.