The holy Tanna (Mishnaic sage) Mattia ben Charash was an awesome rightoeus man. Born in Judea right after the destruction of our Second Holy Temple, Rebbe Mattia was a student of Rebbe Ishmael and a contemporary of Rebbe Shimon Bar Yochai. For the sake of Torah, he fled the Hadrianic persecutions in the Land of Israel and went to Rome, where he founded an outstanding Torah academy, or yeshiva.
 
Rebbe Mattia was extremely lenient in the mitzvoth between man and G-d, such as Shabbat. But, he was very exacting in two areas - the mitzvot between man and fellow man and the mitzva of personal holiness and specifically guarding one's eyes.
 
In the Ethics of our Fathers (Pirkei Avot 4:20), he teaches, "Greet everybody you meet by saying "Shalom"; and try to be a "tail" to lions (in other words, associate with people who are greater than you), rather than the head of foxes." As we can see, Rebbe Mattia placed great emphasis on humility and kindness, both of which are closely associated with personal holiness, as we see in the famous Midrash (Yalkut Shimoni, Vayechi

) about how the Satan did his utmost to tempt Rebbe Mattia:
 
Rebbe Mattia ben Charash who would always be sitting in the Hall of Study engaged in torah study; the brilliance of his face resembled the sun and his countenance resembled that of the ministering angels, because he had never raised his eyes to look at women.
 
Once the Satan focused his sight on this Tzaddik and said to himself: "Is it possible that this man does not sin?" Then the Satan went and asked G-d: "How do you regard Rebbe Mattia ben Charash?"
 
Hashem replied: "He is a perfect Tzaddik"
 
The Satan said to G-d: "Give me permission to test him".
 
Hashem told the Satan: "Go ahead".
 
The Satan appeared to the Rebbe Mattia as a beautiful woman the like of which there had never been in the world. When the Tzaddik saw he immediately turned his face away from the woman, she quickly moved to the side where Rabbi Mattia had turned his face to, and he quickly again turned his face away from that woman  to the other side.
 
Then the Tzaddik said: "I am afraid that my Yetzer HaRa (evil inclination) will overpower me and will cause me to sin". So what did he do? He called a student that was there with him and ordered him to bring him fire with nails. The student brought him the nails, and Rebbe Mattia put them in the fire until they were red hot. He then stabbed his eyes with the hot nails and became blind.
 
When the Satan saw this he trembled and fell over backwards.
 
At that time The Holy One Blessed be He called the angel Raphael (for he is in charge of healing) and told him: "Go and heal Rebbe Mattia ben Charash".
 
Raphael the Archangel came in front of Rebbe Mattia, who asked: "Who are you?"
 
The angel replied: "I am Raphael the angel, I came here because Hashem sent me to cure your eyes".
 
Rebbe Mattia ben Charash replied: "Leave me alone, what is already done is what will be".
 
Raphael returned before the Holy One Blessed be He and said: "Master of the World, thus spoke Mattia".
 
G-d said to him: "Go back to him and tell him that I will personally guarantee that the Yetzer Hara will have no power over him".
 
Immediately Raphael went and cured Mattia.From here Our Sages said: "All those that are careful not to look at women, the Evil Inclination has no power over them".
 
I strongly suggest that you make a trip to Rebbe Mattia's gravesite. It's right by the Israel National Water Carrier (Movil Artzi) accross the road from the Arab village Eilabun, north of the Golani crossroads and west of Tiberias, on the eastern tip of the scenic Bet Netufa Valley. It's a great place to pray for personal holiness.