Rahula was the Buddha's only child (A.I,24). He may have been given this name because he was born during or around the time of a lunar eclipse (ràhu).
It was just after his birth that the Buddha finally decided to renounce the world, become a monk and embark on his quest for truth. About seven or perhaps eight years later the Buddha returned to Kapilavatthu, met Ràhula for the first time, had him ordained as a novice monk and took him away with him.
This caused considerable distress to both the Buddha's former wife, Yasodhara, and also to his father Suddhodana. Probably the Buddha felt he would be able to give his son a more spiritually-based education than he would get if he stayed at home. Ràhula grew up to be a well-disciplined monk and eventually became enlightened. He commented, ‘They call me “Ràhula the lucky” for two reasons; because I am the Buddha's son and because I am at one with the truth (Th.295). Other than a few scraps of information, the Tipitaka gives little information about Ràhula. Two discourses in the Majjhima Nikaya by the Buddha are addressed to his son (M.I,414, 421).
- Buddhism A to Z. Ven. Dhammika, 2007.