AN ELEPHANT LONGS FOR HIS PARENTS
Dhanapalako nama kunjaro katukappabhedano dunnivarayo
Baddho kabalam na bhunjati sumarati naga vanassa kunjaro.
During the rutting season, Dhanapala eats not even a morsel and is uncontrollable.
Held in captivity, the tusker only calls to mind the elephant forest. (i.e. longing to look after his parents). 
Once, there lived in Savatthi an old brahmin who was extremely rich. He had four sons and when each of the sons got married, he gave him a share of his wealth. Then, he gave away half of his remaining property to them. Later, his wife died. His sons came to him and looked after him very well and they were very loving and affectionate to him. During the course of time, somehow they influenced him to give them the other half of the remaining property. Thus, he was left penniless.
First he went to stay with his eldest son. After a few days, the daughter-in-law said to him, 'Did you give any extra wealth to your eldest son? Don't you know the way to the house of your other sons?' Hearing this, the old brahmin got very angry and left the eldest son's house for the house of his second son. The same remarks were made by the wife of his second son and the old man went to the house of his third son and finally to the house of the fourth and youngest. Thus, the old man was left destitute and taking a staff and a bowl he went to the Buddha for protection and advice.
At the monastery, the brahmin told the Buddha how his sons had mistreated him. The Enlightened One taught him some verses and advised him to recite them wherever there was a large gathering of people. The gist of the verses is this: 'My four foolish sons are like ogres. They call me 'father, father' but the words come only out of their mouths and not from their hearts. They are deceitful and scheming. Taking the advice of their wives they have driven me out of their houses. So, now I have been reduced to begging. Those sons are of less service to me than this staff of mine.'
When the appointed day came for the brahmins of Savatthi to hold their meeting and knowing that his sons would be there, the old brahmin also attended the meeting. Now at that time, this was the prevailing law: Whoever ill-treats his mother or father and does not support or look after them shall be punished. Many people in the crowd, on hearing the verses recited by the old brahmin, went wild with rage at the ungrateful sons and threatened them for neglecting their father.
Then the sons realised their mistakes and knelt down at the feet of their father and asked for pardon. They also promised that starting from that day they would look after him properly and would respect, love and honour him. They also warned their wives to look after their father well. Each of the sons gave him proper food and clothing. Thus the brahmin became healthier. So, he went to the Buddha and humbly requested him to accept two food-trays out of the four he was receiving every day from his sons.
One day, the eldest son invited the Buddha to his house for almsfood. After the meal, the Buddha gave a discourse on the benefits to be gained by looking after one's parents. Then he related to them the story of the elephant called Dhanapala, who looked after his parents. Dhanapala when captured pined for the parents who were left in the forest.