Charles H. Spurgeon on Psalms 120:4

Sharp arrows of the mighty. Swift, sure, and sharp shall be the judgment. Their words were as arrows, and so shall their punishment be. God will see to it that their punishment shall be comparable to an arrow keen in itself, and driven home with all the force with which a mighty man shoots it from his bow of steel, —"sharp arrows of the mighty". Nor shall one form of judgment suffice to avenge this complicated sin. The slanderer shall feel woes comparable to coals of juniper, which are quick in flaming, fierce in blazing, and long in burning. He shall feel sharp arrows and sharper fires. Awful doom! All liars shall have their portion in the lake which burneth with fire and brimstone. Their worm dieth not, and their fire is not quenched. Juniper coals long retain their heat, but hell burneth ever, and the deceitful tongue may not deceive itself with the hope of escape from the fire which it has kindled. What a crime is this to which the All merciful allots a doom so dreadful! Let us hate it with perfect hatred. It is better to be the victim of slander than, to be the author of it. The shafts of calumny will miss the mark, but not so the arrows of God: the coals of malice will cool, but not the fire of justice. Shun slander as you would avoid hell.