Why the "Ave Maria" quote at the end of Widmung?

Utako just played (beautifully) Schumann's "Widmung" during today's Virtual Musicale, where I raised the question, why did Schumann quote Ave Maria at the end? I googled that, briefly, and found some info:

* Widmung is a song composed by Robert Schumann, Opus 25

* Good friend Liszt wrote the piano transcription (the piano accompaniment to the song is challenging enough!)

* The text is by poet Friedrich Rückert - it is a love song

* Widmung was Robert's wedding gift to Clara

"Ave Maria was supposedly a favorite of Clara’s and often heard at weddings. Schumann wrote this piece in 1840, during his “year of song” and wrote it, along with the rest of Op.25, for his beloved Clara as a wedding gift."

If anyone knows anything more, please elaborate...