The Priestly Source (P) is one of the sources of the Torah/Pentateuch in the bible, together with the Yahwist and the Deuteronomist. Primarily a product of the post-Exilic period when Judah was a province of the Persian empire (the 5th century BCE), P was written to show that even when all seemed lost, God remained present with Israel. It has been compared to a necklace strung with pearls: "the thread of the necklace is made up of genealogies, itineraries and a terse story line, with a strong interest in chronology ... [t]he pearls are the major stories". Its characteristics include a set of claims that are contradicted by non-Priestly passages and therefore uniquely characteristic: no sacrifice before the institution is ordained by God at Sinai, the exalted status of Aaron and the priesthood, and the use of the divine title El Shaddai before God reveals his name to Moses, to name a few.
The history of exilic and post-exilic Judah is little known, but a summary of current theories can be made as follows: