Philemon and Baucis, in the Greek mythology a pair of poor people who, in fond attachment to each other, lived in a small cottage in Phrygia by themselves and gave hospitality to gods in disguise when every other door was shut against them, and to whom, in the judgment that descended upon their inhospitable neighbours, the gods were propitious, and did honour by appointing them to priesthood, when they would rather have been servants, in a temple metamorphosed out of their cottage. Here they continued to minister to old age, and had but one prayer for themselves, that they might in the end die together; when as they sat at the door of the temple one day, bent with years, they were changed, he into an oak and she into a linden. This is Ovid's version of the story, to which he adds as the moral of it, “Those who piously honour the gods are themselves held in honour.”
Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)
Philemon, Epistle to * Philip