According to the Book of Genesis, Pharez/Pיrez (Hebrew: פֶּרֶץ / פָּרֶץ, Standard Péreẓ / Páreẓ Tiberian Péreṣ / Pāreṣ ; "Breach") was the son of Tamar and of Judah, and was the twin of Zerah^[1]. The text argues that he was called Perez because he was the first twin to be born, and thus had breached the womb^[2]. According to biblical scholars, the birth narrative here is an eponymous aetiological myth concerning the ethnological origin of parts of the tribe of Judah^[3]^[4].

The book of Ruth lists Perez as being part of the ancestral genealogy of King David^[5], and the Book of Matthew consequently mentions him when specifying the genealogy of Jesus^[6]