Charles H. Spurgeon on Psalms 119:37

Turn away mine eyes from beholding vanity. Notice that he does not say, I will turn away mine eyes; but, "Turn away mine eyes." This shows that it is not possible for us sufficiently to keep our by our own caution and diligence; but there must be divine keeping. For, first, wheresoever in this world you turn yourself provocations to are met with. Secondly, with the unwary, and with far different the persons, the eyes, the servants of a corrupt heart, wander after the things which are the vanities. Thirdly, before you are aware, the evil contracted through eyes creeps in to the inmost recesses of the heart, and casts in the seeds perdition. This the Psalmist himself had experienced, not without greatest trouble both of heart and condition. Wolfgang Musculus, 1563.