On the Contemplative Life §68 — C. D. Yonge, The Works of Philo Judaeus (1854–55), public domain (public domain)
(68) And the women also share in this feast, the greater part of whom, though old, are virgins in respect of their purity (not indeed through necessity, as some of the priestesses among the Greeks are, who have been compelled to preserve their chastity more than they would have done of their own accord), but out of an admiration for and love of wisdom, with which they are desirous to pass their lives, on account of which they are indifferent to the pleasures of the body, desiring not a mortal but an immortal offspring, which the soul that is attached to God is alone able to produce by itself and from itself, the Father having sown in it rays of light appreciable only by the intellect, by means of which it will be able to perceive the doctrines of wisdom.
Reproduced in full. Translation: C. D. Yonge, The Works of Philo Judaeus (1854–55), public domain (Public domain).
Why Pitre cites it
The Therapeutae include 'aged virgins, who have kept their chastity not under compulsion, like some of the Greek priestesses, but of their own free will' — consecrated virginity in first-century Judaism.
Notes
Passage located and complete, but the key phrase as given ('aged virgins, who have preserved their chastity, not out of necessity ... but from their own free will') is the Loeb/Colson wording. Yonge reads: 'the greater part of whom, though old, are virgins in respect of their purity (not indeed through necessity ... ), but out of an admiration for and love of wisdom'. Same sense, different words.