Mus'ab bin Sa'd narrates from his father, Sayyiduna Sa'd (may Allah be pleased with him), that a man spoke insultingly of Sayyiduna Ali (may Allah be pleased with him), so Sayyiduna Sa'd bin Malik (may Allah be pleased with him) supplicated against him. Suddenly a she-camel or a camel came and killed him (by trampling him). After this incident, Sayyiduna Sa'd (may Allah be pleased with him) freed a soul (a slave) and swore that he would never again supplicate against anyone.