Takkala Jātaka (No.446)
Once in a village lived a man called Saviṭṭhaka, an only son, who looked after his father with great devotion, until the latter, much against the wishes of his son, found a wife for him. A son was born to the pair and, when seven years old, he overheard his mother planning to have the old man taken by a ruse to the cemetery and there killed and buried in a pit. The next morning, when his father set out in a cart for the cemetery, the child insisted on accompanying him. Having watched his father dig a pit, he asked what it was for, and was told that the useless old man was a burden to keep and that the pit was for him. The boy was silent, and when his father stopped to have a rest, he took up the spade and began to dig another hole. On being asked the reason, he said it was for his father when he should be too old to be supported. This remark opened Saviṭṭhaka’s eyes; he returned home and drove away his wife. He afterwards took her back on her promising to give up her treacherous ways.
The story was related to a man who had looked after his father; but the wife, whom he took at his father’s wish, wanted to get rid of the old man, and suggested the idea to her husband. However, his answer was that if she found the house inconvenient she could go elsewhere. The Buddha said that the characters of both stories were identical, and that he himself was the lad of the story of the past (atītavatthu). J.iv.43‑50.