An eminent Commentator of Ceylon, teacher of Tipitaka Cūlanāga. The pupil seems to have disagreed with some of the explanations of his teacher - e.g., as to the meaning of ekāyanamagga. Cūlanāga said it referred to pubbabhāgasatipatthānamagga, but Cūlasumma held that it referred to missakamagga. They could come to no decision; but while on his way to the bathing-place, Cūlasumma revolved the problem in his mind, and discovering that his pupil was right announced his mistake when Cūlanāga was preaching on the day of the first quarter. Cūlanāga, realising how even his teacher could go astray on this point, explained it at great length for the benefit of future generations (DA.iii.744f.; MA.i.187). The Anguttara Commentary (AA.ii.845) calls him Dīpavihāravāsī, while the Vibhanga Commentary (p.489; probably Cūlasumma is here a misreading for Cūlasumana) says that he dwelt in Ninkaponnapadhānaghara in Cittalapabbata. The Samantapāsādikā (iv.892) says that he lived in Rohana.