Note 21 — Chapter XVI · ON TO MATHURÂ OR MUTTRA. CONDITION AND CUSTOMS OF CENTRAL INDIA; OF THE MONKS, VIHÂRAS, AND MONASTERIES.
James Legge translation
The eldest son of Śâkyamuni by Yaśodharâ. Converted to Buddhism, he followed his father as an attendant; and after Buddha’s death became the founder of a philosophical realistic school (vaibhâshika). He is now revered as the patron saint of all novices, and is to be reborn as the eldest son of every future Buddha. Eitel, p. 101. His mother also is to be reborn as Buddha.