BLESSED INDEED ARE THEY WHO HONOUR THOSE WORTHY OF HONOUR
Abhivadanasilissa niccam vaddhapacayino
Cattaro dhamma vaddhanti ayu vanno sukham balam.
For one who is in the habit of constantly honouring and respecting the elders, four blessings increase - age, beauty, bliss, and strength. 
Once, there were two hermits who lived together practising religious austerities for many years. Later, one of them left the hermit life and got married. After a son was born, the family visited the old hermit and paid their respects to him. To the parents the hermit said, 'May you live long', but he said nothing to the child. The parents were puzzled and asked the hermit the reason for his silence. The hermit told them that the child would live only seven more days and that while he himself did not know how to prevent his death, Gotama, the Buddha, might know how to do it.
So the parents took the child to the Buddha. When they paid homage to the Buddha, he also said, 'May you live long' to the parents only and not to the child. The Buddha also knew of the impending death of the child. To prevent his death, the parents were told to build a pavilion at the entrance to the house, and put the child on a couch in the pavilion. Then some bhikkhus were sent there to chant the Parittas*for seven days. On the seventh day, the Buddha himself came to that pavilion; the devas were also in attendance. At that time, an evil spirit was at the entrance, waiting for a chance to attack the child, but as more powerful devas arrived the demon had to step back and make room for them so that he had to stay at a place very far away from the child. That whole night, recitation of parittas continued, thus protecting the child. The next day, the child was taken up from the couch and made to pay respects to the Buddha. This time, the Buddha said, 'May you live long' to the child. When asked how long the child would live, the Buddha replied that he would live up to one hundred and twenty years. So the child was named Ayu Waddhana.
When the child grew up, he went about the country with his friends and fellow devotees. One day, they came to the Jetavana monastery, and the bhikkhus, recognising him, asked the Buddha, 'For living beings, is there any means of gaining longevity?' To this question, the Buddha answered, 'By respecting and honouring the elders and those who are wise and virtuous, one would gain not only longevity but also beauty, happiness and strength.'
*Parittasare religious stanzas orsuttas(like theMetta Suttaand theRatana Sutta) that are usually recited for protection against harmful influences.