Before ascending Tavatimsa heaven, the Buddha described seven categories of Abhidhamma to the Venerable Sariputta Thera. Thereafter, the Venerable had 500 disciples of the Buddha assemble and described them the seven categories of Abhidhamma given by the Buddha. After the sermon, all monks attained the Enlightenment.
Colophon:
See DS0011_00643, folio 14 on the recto and verso sides.