Ralph Erskine (The Nature and Excellency of Purity opened), Sermons 1:299:
I will tell you of five stones that you should daily cast at your lusts. (1.) The stone of instituted means and appointed ordinances. Is prayer a mean? is the word a mean? Use these means in the Lord’s strength. (2.) The stone of scriptural argument, such as Joseph’s argument: “Shall I do this great wickedness, and sin against God?” David’s argument: shall I do so and so? “Then would I offend the generation of the righteous.” (3.) The stone of gospel-promises, such as that: “I will sprinkle clean water upon you, and ye shall be clean. I will give you a new heart and a new spirit,” etc. “Having these promises, let us cleanse ourselves from all filthiness of flesh and spirit.” Plead the promises and cry for the grace promised. (4.) The stone of Christ’s mediation and prayer; John 17:15, 17, “Sanctify them through thy truth, thy word is truth.” “While they are in the world, keep them from the evil of it.” Improve the intercession of Christ. (5.) The stone of Christ’s death and passion. His crucifixion is that in the virtue whereof sin is crucified. Improve his death and look for virtue to come from thence. – Look to the Lord for grace and skill to cast these stones into the head of Goliath.