It looks like there is an error in the icon. There appear to be letters missing here and there. It is likely supposed to be from Zachariah 1:3: επιστρέψατε πρός με, λέγει Κύριος των δυνάμεων - Turn unto me, says the LORD of hosts.
I'll try and investigate it further.
"O Cross of Christ, all-holy, thrice-blessed, and life-giving, instrument of the mystical rites of Zion, the holy Altar for the service of our Great Archpriest, the blessing - the weapon - the strength of priests, our pride, our consolation, the light in our hearts, our mind, and our steps"
Met. Meletios of Nikopolis & Preveza, from his ordination.