In 1822 Schubert set Rückert’s five-verse poem, Sei mir gegrüßt (I greet you), to music, and it became one of the most exquisite of his love songs. Five years later, it found its way to the slow movement, a set of variations, of his Fantasy for Violin and Piano.
On Youtube you may find many different interpretations of the Lied, and here are two: First by baritone Dietrich Fischer-Dieskau and pianist Gerald Moore:
And a more recent live recording by tenor Ian Bostridge and pianist Juilius Drake:
You may find the original poem and English translation on the Lied and Art Song Texts website here.
Enjoy!