Ὅτι σοῦ ἐστιν ἡ βασιλεία καὶ ἡ δύναμις καὶ ἡ δόξα, τοῦ Πατρός καὶ τοῦ Υἱοῦ καὶ τοῦ Ἁγίου Πνεύματος εἰς τοὺς αἰῶνας τῶν αἰώνων. Ἀμήν. → For thine is the kingdom, and the power, and the glory, of the Father, and of the Son, and of the Holy Spirit forever and ever. Amen.

[Frederique]

Ὅτι σοῦ ἐστιν ἡ βασιλεία καὶ ἡ δύναμις καὶ ἡ δόξα, τοῦ Πατρός καὶ τοῦ Υἱοῦ καὶ τοῦ Ἁγίου Πνεύματος εἰς τοὺς αἰῶνας τῶν αἰώνων → For thine is the kingdom, and the power, and the glory, of the Father, and of the Son, and of the Holy Spirit (Holy Ghost) forever and ever. Amen

(Matthew 6:13, Byzantine text, modified)
Bill, please correct the accents for me :)

[billberg23]

Done.  Who inserted the formula τοῦ Πατρός καὶ τοῦ Υἱοῦ καὶ τοῦ Ἁγίου Πνεύματος into Matthew 6:13 (Byzantine text:  cf. Textual Variants: Matt. 1:10-10:3)?  Is it from an orthodox rite/prayer? 

[Frederique]

I'm not sure. The inscription is in a tiny religious locket (not old) from a church/monastery on the island of Kyra Panagia