Roger Pearse just put another of the patristic translations he has commissioned. This one is a fragmentary Commentary on Luke, attributed to Eusebius, and derived from bits of an 11th century catena collection.
Whoever wrote it, it includes some beautiful thoughts.
Here’s what it has about Mary’s fiat:
“I am the handmaiden of the Lord.
I am the writing-tablet. Let the scribe write what He wills.
Let the Lord of all do as He wills.
Let it be done to me according to thy word.“