Charles H. Spurgeon on Psalms 119:78

Let the proud be ashamed. This suggests a word to the wicked. Take heed that by your implacable hatred to the truth and church of God you do not engage her prayers against you. These imprecatory prayers of the saints, when shot at the right mark, and duly put up, are murdering pieces, and strike dead where they light. "Shall not God avenge his own elect, which cry day and night unto him, though he bear long with them? I tell you that he will avenge them speedily." Luke 18:7-8. They are not empty words as the imprecations of the wicked poured into the air, and there vanishing with their breath but are received into heaven, and shalt be sent back with thunder and lightning upon the pates of the wicked. David's prayer unravelled Ahithopel's fine spun policy, and twisted his halter for him. The prayers of the saints are more to be feared as once a great person said and felt than an army of twenty thousand men in the field. Esther's fast hastened Haman's ruin, and Hezekiah's against Sennacherib brought his huge host to the slaughter, and fetched an angel from heaven to do the execution in one night upon them. William Gumall.