Varuṇa Jātaka (No.71)
The Bodhisatta was once a teacher of Takkasilā, with five hundred brahmin pupils. One day he sent the pupils into a forest to gather wood, but one of them was lazy and went to sleep, and when his companions woke him he climbed on to a tree and broke off some green branches. One of the boughs hit him in the eye and wounded him. The next day the pupils had been invited to a meal in a distant village and a servant girl was told to make them some gruel early, before their start. She lit a fire with the green wood which lay on the top of the firewood, and the fire would not burn. The green wood had been thrown there last by the lazy pupil who had been the last to return. The pupils could not start in time and the journey had to be abandoned.
The story was told in reference to Kuṭumbiyaputta Tissa, with whom the brahmin youth is identified. J.i.316 ff.