Source of text is two poems, both entitled "Philomena": the 1st part is the opening stanza of a work first attributed to St. Bonaventura and later to various 13c authors, including John of Peckham, Archbishop of Canterbury. Part 2 is paraphrased from lines of a work of Juventinus Albus Ovidus.
Philomena prævia temporis amœni,
Quae recessum nuntias imbris atque cæni.
Dum demulces animas tuo cantu leni,
Avis prædulcissima ad me quæso veni.
Veni, veni, dulcis amica,
Veni, noctis solatia praestans;
Inter enim volucres nulla tibi similis.
English translation
O nightingale, harbinger of temperate times,
That foretells the retreat of rainstorms and mirk
Whilst you soothe the spirit with your sweet warbling;
Prithee come to me, thou sweetest bird.
Come, O come sweet friend,
Come, supreme night-time comforter;
For you are unique amongst birds.
(trans. Timmi O'Danaos & Donna Ferrentes)
German translation
Heroldin des Lenzes du, süßes Philomele,
kündend, daß der Winter nun uns nicht länger quäle,
Wenn du Ohr und Herz erfreu'st mit der Flöten kehle;
Komm zu mir, ich grüsse dich, Vöglein voller Seele!
(Melchior von DiepenbrockGeistlicher Blumenstrauss 1854)