Nineteen in Astronomy and the Quran

Nineteen has a genuine astronomical basis in the Metonic cycle: nineteen solar years are very nearly equal to two hundred and thirty-five lunar months, so the phases of the moon recur on the same calendar dates every nineteen years. This relation, known to the Babylonians and named for the Greek Meton, underlies the lunisolar calendars of Judaism and the calculation of Easter. The Quran states at 74:30 that over the fire are nineteen, a verse whose brevity has invited much commentary; in the twentieth century Rashad Khalifa built on it an elaborate claim that the text is structured throughout on the number nineteen, a theory that gained a following and then wide rejection within mainstream Islam, and which is best treated as a modern and contested reading rather than a traditional one.

Balliett's 1908 chart reduces nineteen to one, initiative and new beginnings in the standard modern keyword list, by way of an intermediate ten; Cheiro's 1926 Book of Numbers instead reads nineteen among his compound numbers as a figure of the sun, promise and success arrived at through one's own effort, a reading Florence Campbell's 1931 book and Juno Jordan's 1965 systematisation both carried forward, and one that has no connection to the Metonic cycle or the Quranic verse already described, since Cheiro built his compound meanings from name-numerology practice rather than from astronomy or scripture.