A frequent guest in the home of the Shunamis was none other than Elisha Hanavi. She told her husband that this man was holy. How did she deduce that fact about Elisha Hanavi? Simply because he had never looked at her.
Chazal say (Midrash Vayikra 24:6) that in matters of arayos, restraint equals holiness. Just taking care to refrain from looking at the forbidden and from thinking lustful thoughts already earns one the title “kadosh”. Rejection of impurity generates holiness. An unfathomable light of holiness envelops the man who conquers his lust - especially when it burns and races inside him.
It is not because Rebbi compiled the Mishnah that we refer to him as Rabbeinu Hakadosh. It’s because he never in his life looked at the private parts of his body and, therefore, his soul was kadosh. In addition, he would never unnecessarily lower his hands below his waist; his body, too, was kadosh (Shabbos 118b).
What better way to bolster our resolve than to repeat the wonderful words that Hashem Himself has to say to us, “If you will give Me your heart and your eyes, then I will know that you are Mine,”) Yalkut Shimoni, Mishlei ch. 27). Neither look at nor contemplate what is sinful, and automatically you qualify to be lifted beyond the grasp and the smallness of this temporal existence and to have Hashem Himself fill every corner of your life.
Sefer Chassidim assures us that even the malachim, those holy celestial beings, cannot approach the place of honour that is reserved for the Yid who (among other things) carefully guards his eyes. In the Next World, he won’t just be sitting among ordinary folk. His coveted seat is among our very greatest - part of that inner circle of which Hashem Himself is the epicentre.
The malachim, having always been pre-programmed to holiness and never having to struggle for it, will be obliged to remain outside the circle of such tzaddikim and will come to them, begging to know, ״What is Hashem doing?״ (see Sefer Chassidim 140).
As for remembering one’s learning, pure eyes will help here too, because shmiras einayim has the propensity to protect our memory, says Rav Shimon Shkop, ztz״l. Yes, pure eyes stand guard over the Torah that one has learned. This is hinted at in the last parsha of Shema by the proximity of the words תתורו ולא - Do not stray after your eyes, to the words תזכרו למען - so that you shall remember.