In Buddhism, a sutra is a sermon of the Buddha or one of his principal disciples. Buddhist sutras usually begin with the traditional words, "Thus I have heard." This is a nod to the story of Ananda, who recited all of the historical Buddha's sermons at the First Buddhist Council and was said to have begun each recitation this way.
The Lotus Sutra begins, "Thus I have heard. At one time the Buddha was in Rajagriha, staying on Mount Gridhrakuta." Rajagriha was a city on the site of present-day Rajgir, in northeastern India, and Gridhrakuta, or "Vulture's Peak," is nearby. So, the Lotus Sutra begins by making a connection to a real place associated with the historical Buddha.
However, in a few sentences the reader will have left the phenomenal world behind. The scene opens to a place outside ordinary time and space. The Buddha is attended by an unimaginable number of beings, both human and nonhuman -- monks, nuns, laymen, laywomen, heavenly beings, dragons, garudas, and many others, including bodhisattvas and arhats. In this vast space eighteen thousand worlds are illuminated by a light reflected by a hair between the Buddha's eyebrows.