The interpretation timeline
The Marburg Colloquy
Luther and Zwingli met over the words of institution and did not agree; the Protestant division on the Eucharist dates from here.
1529
Marburg
Reformation
c. 1500 – 16501529
Event
The Marburg Colloquy
At Marburg, Luther and Zwingli agree on fourteen articles of faith; the fifteenth records that they could not agree whether the true body and blood of Christ are bodily present in the bread and wine.
Modern · 1953 →
The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.