Charles H. Spurgeon on Psalms 64:7

But God shall shoot at them with an arrow. They shot, and shall be shot. A greater archer than they are shall take sure aim at their hearts. One of his arrows shall be enough, for he never misses his aim. The Lord turns the tables on his adversaries, and defeats them at their own weapons. Suddenly shall they be wounded. They were looking to surprise the saint, but, lo! they are taken at unawares themselves; they desired to inflict deadly wounds, and are smitten themselves with wounds which none can heal. While they were bending their bows, the great Lord had prepared his bow already, and he let slip the shaft when least they looked for such an unsparing messenger of justice. "Vengeance is mine; I will repay, saith the Lord." The righteous need not learn the arts of self defence or of attack, their avenging is in better hands than their own.