The vigil referenced in the title is Shemira, a Jewish custom in which a guardian, usually a relative or close friend, spends the night in the same room as the recently deceased before a morning funeral. The guardian spends the night standing and reading the Torah, to prevent Satan from possessing the deceased or the guardian.
The dialogue is in English and Yiddish, a germanic language that uses the hebrew alphabet.
In December 2019, Blumhouse acquired domestic distribution rights to the film.