Homily III on the Mother of God, 671 — as quoted by Pitre (pp 61–62); translation: Mary Hansbury, Jacob of Serug: On the Mother of God (St Vladimir's Seminary Press, 1998)
The Mother, Virgin and blessed, was even more beautiful than the Ark full of mysteries of the house of God…While the Ark was being carried, David had danced for joy…He typified in figure the way of Mary with John [the Baptist], for also that maiden was the Ark of the Godhead.
No freely usable English translation of this passage is online, so the note keeps Pitre's quotation and links to the full text. Translation: Mary Hansbury, Jacob of Serug: On the Mother of God (St Vladimir's Seminary Press, 1998), as quoted by Pitre.
In Jewish Roots of Mary
Why it is cited
'The Mother, Virgin and blessed, was even more beautiful than the Ark… that maiden was the Ark of the Godhead.' Jacob sees David's dance before the Ark fulfilled in John leaping before Mary.