Charles H. Spurgeon on Psalms 35:15

"But in mine adversity they rejoiced," etc. —Do not glory in your neighbour's ruins. The fire-fly leaps and dances in the fire, and so do many wicked men rejoice in the sufferings of others. Such as rejoice in the sufferings of others are sick of the devil's disease; but from that disease the Lord deliver all your souls. 'Tis sad to insult over those whom God hath humbled; 'tis high wickedness to triumph over those to whom God hath given a cup of astonishment to drink. Such as make the desolations of their neighbours to be the matter either of their secret repast, or open exultation, such may fear that the very dregs of divine wrath are reserved for them. 'Tis bad playing upon the harp because others have been put to hang their harps upon the willows. We must not pray with him in the tragedy, but it may rain calamities; nor with Clemens' Gnostic, Give me calamities that I may glory in them. There cannot be a greater evidence of a wicked heart, than for a man to be merry because others are in misery. "He that is glad at calamities (that is, at the calamities of others) shall not be unpunished." Prov. 17:5. If God be God, such as congratulate our miseries instead of condoling them, shall be sure to be punished with the worst of punishments; for such do not only sin against the law of grace, but also against the very law of nature; the law of nature teaching men to sympathise with those that are in misery, and not to rejoice over them because of their miseries. O, sirs, do not make others' mourning your music, do not make others' tears your wine; as you would not be made drunk at last with the wine of astonishment. —Thomas Brooks.