Simplify the following text for a Grade 10 native English-speaking person.
Original: Saint Thomas Aquinas spoke of the name `` Mary '' , indicating who was the `` full of grace '' person addressed , as the only word that had been added in the West even by the mid-thirteenth century to the Biblical verses of which the prayer was composed .
Simplified: Saint Thomas Aquinas spoke of the name `` Mary '' , which served to indicate who was the `` full of grace '' person mentioned , as the only word added at his time to the Biblical text .