It's written in a very old way of Church Slavonic writing, so it's very difficult to read it. Here is a better resolution:
For sure it's prophet Gedeon from the Book of Judges. The first word is "Az" means "I", the second one I suppose is "runo" means "fleece". The 3rd one is probably "Tya" meaning "you". The next one is "prezhde" meaning "before".
Moreover the last word is hidden in the middle and probably has a "titlo" (abbrevation used for holy words).
I tried to find something in the Bible in Church Slavonic, as usually Old Testament saints keep in their hands rolls with the words from it, but it seems this time it's an abbreviation or a paraphrase.
Furthemore, I've searched for other icons of st. Gedeon and on each one there are different words, however this one is the most similar: