The "exegetical tradition" means the vast corpus of Latin writings, often biblical commentaries, sermons or preaching handbooks, diatribes against doctrinal deviancy and philosophical explorations, in which scholars of the medieval Church present the Bible according to medieval orthodoxy.
It includes most religious drama, much stained glass and some wild and fanciful retellings of Bible stories.
The Bible itself does not say what kind of fruit it was, but in the popular retelling, as opposed to the theological schools, it became an apple.
In the medieval understanding of biblical truth, there was no need for a modern style of debate on the accuracy of the motif.
The term medieval popular Bible became established in scholarship relatively recently as a result of the writings of Brian O. Murdoch, though the phrase had been used before him, usually in a less clearly defined way.