Homily I on the Dormition, 2 — as quoted by Pitre (p 86); translation: Brian E. Daley, On the Dormition of Mary (St Vladimir's Seminary Press, 1998)
Neither the human tongue nor the mind of the angels that live beyond this universe can give worthy praise to her, through whom it has been granted us to gaze clearly on the glory of the Lord…Let us, in holy reverence, with trembling hand and yearning soul, pay gratefully the humble first-fruits of our minds, as we must, to the Queen Mother, the benefactress of all nature!
No freely usable English translation of this passage is online, so the note keeps Pitre's quotation and links to the full text. Translation: Brian E. Daley, On the Dormition of Mary (St Vladimir's Seminary Press, 1998), as quoted by Pitre.
Why Pitre cites it
'Let us… pay gratefully the humble first-fruits of our minds, as we must, to the Queen Mother, the benefactress of all nature!' — the queen mother's title in the eighth century.