When Shabbat ends and three stars appear in the sky, Jewish custom has always lingered a little longer over the Sabbath queen's departure. One of the oldest customs is to sing hymns and recite legends about Elijah the prophet. This is not nostalgia. It is practical theology.
The Tosefta, compiled around 220 CE, teaches that at the close of every Sabbath, Elijah sits under the Tree of Life in the Garden and records in writing the merits of those who have kept the Sabbath just completed. He is the scribe of Sabbath observance. And because Elijah is also the herald who will announce the coming of the Mashiach, the messiah, every Saturday night he is already at his post, pen in hand, preparing the paperwork of redemption.
The especially pious have a further practice. They write the phrase "Elijah the Prophet" over and over again, and the particular are told to write it exactly 130 times. The number is not arbitrary. The Hebrew letters of Eliyahu HaNavi add up, by the system of gematria, to 120. Add 10 for the count of the letters themselves, and you reach 130.
The custom is a small private summoning, performed in the margin of a notebook or on a scrap of paper. Some write the phrase a hundred and thirty times in ink. Some simply repeat it under their breath. Each repetition is a whisper toward the Tree of Life: we have kept the Sabbath. Write us in. Hurry the day you will come to announce.