This is the Canticle of St. Simeon, traditionally sung at Compline:
Nunc dimittis servum tuum, Domine, secundum verbum tuum in pace:
Quia viderunt oculi mei salutare tuum
Quod parasti ante faciem omnium populorum:
Lumen ad revelationem gentium, et gloriam plebis tuæ Israel.
Gloria Patri, et Filio, et Spiritui Sancto,: sicut erat in principio, Et nunc, et semper: et in sæcula sæculorum. Amen.
Here is a chanted recording of this Latin text.
νῦν ἀπολύεις τὸν δοῦλόν σου, δέσποτα, κατὰ τὸ ῥῆμά σου ἐν εἰρήνῃ·
ὅτι εἶδον οἱ ὀφθαλμοί μου τὸ σωτήριόν σου,
ὃ ἡτοίμασας κατὰ πρόσωπον πάντων τῶν λαῶν,
φῶς εἰς αποκάλυψιν ἐθνῶν καὶ δόξαν λαοῦ σου Ἰσραήλ.
Here is a chanted recording of this Greek text.
English (Douai Reims Translation):
Now thou dost dismiss thy servant, O Lord, according to thy word in peace;
Because my eyes have seen thy salvation,
Which thou hast prepared before the face of all peoples:
A light to the revelation of the Gentiles, and the glory of thy people Israel.
Glory be to the Father, and to the Son, and to the Holy Spirit: as it was in the beginning, is now, and ever shall be, world without end. Amen.
Here is a chanted version of the Nunc Dimittis in English.