Dasuttarasutta

Suttapiṭaka · Dīghanikāya · Pāthikavagga · Vol. 11 · Section 406

[406] What four things are hard to penetrate (duppaṭivijjhā)? Four kinds of concentration (samādhi): concentration partaking of decline (hānabhāgiyo samādhi), concentration partaking of stability (ṭhitibhāgiyo samādhi), concentration partaking of distinction (visesabhāgiyo samādhi), and concentration partaking of penetration (nibbedhabhāgiyo samādhi). These four things are hard to penetrate.

English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.