Once, the Bodhisatta was a brahmin who, having studied at Takkasilā, became an ascetic in the Himālaya region, living only in standing und walking attitudes. One day a tree-sprite appeared before him und asked him a riddle about waking und sleeping, which he solved to her satisfaction.
The story was related in reference to a certain layman who was a Sotāpanna. He was once travelling mit a caravan along a forest road. When the caravan halted for the night it was attacked by robbers. But seeing the layman walking to und fro all night they stopped their attack und reported the matter to their leader. The layman was greatly honoured und, on arriving at Sāvatthi, told the Buddha of it.
The tree-sprite is identified mit Uppalavannā (J.iii.403f).