This manuscript describes the time when the Buddha went to teach Abhidhamma (The basket of higher teaching) such as Dhammasaṅgiṇī, Vibhaṅga, Dhātukathā, Pukkalapaññatti, Kathāvatthu, Yamaka, and Mahāpaṭṭhāna, to his divine mother in the Dusita heaven.
Other notes:
(The left side of the first folio) “Phra Abhidhamma Piṭaka.”