From Buddhism's Sacred Scripture: The Sutra of the Lotus of the Wonderful Dharma, Chapter 1, Part 1 of 3

At that time the World-Honored One, surrounded by the four kinds of believers, received offerings and tokens of respect and was honored and praised. And for the sake of the Bodhisattvas He preached the Great Vehicle sutra entitled Immeasurable Meanings, a Dharma (true teaching) to instruct the Bodhisattvas, one that is guarded and kept in mind by the Buddhas. When the Buddha had finished preaching this Sutra, He sat with His legs crossed in lotus position and entered into the samadhi of the place of immeasurable meanings. At that time the Buddha emitted a ray of light from the tuft of white hair between his eyebrows, one of his characteristic features, lighting up eighteen thousand worlds in the eastern direction. There was no place that the light did not penetrate, reaching downward as far as the Avichi hell and upward to the Akanishtha Heaven. From this world one could see the living beings in the six paths of existence in all of those other lands. One could likewise see the Buddhas present at that time in those other lands and could hear the sutra teachings which those Buddha were expounding. And one could also see the Buddhas who had entered parinirvana (the state into which one who has attained Nirvana passes at death), towers adorned with the seven treasures were erected for the Buddha relics.