Kitāb al-Muʾmin
Hadith 200200 - وعن أبي عبد الله عليه السلام أنه قال: لا تبدأ الشماتة بأخيك 8 المؤمن، فيرحمه الله عز وجل، ويغير ما بك، قال: ومن شمت بمصيبة نزلت بأخيه، لم يخرج من الدنيا، حتى يغير ما به.
200. It has been reported that Abu 'Abd Allah (a.s) said: Do not rejoice at the misfortune of your brother-in-faith lest Allah [M.G] should have mercy on him and change your condition. The Imam also said: One who rejoices at a misfortune that has befallen his brother will not leave this world before his condition changes to the worse.