Final answer:
Oedipus' beard is wet from the tears released by his lacrimal glands.
Step-by-step explanation:
In the play 'Oedipus Rex,' when Oedipus moans and strikes his eyes with his hand, it causes his 'ensanguined orbs' to release a black gory downpour that wets his beard. Anatomically, Oedipus' tears are coming from his lacrimal glands, which are located above the outer corner of each eye.
Learn more about Anatomy of tear production in Oedipus Rex