Ibn Mas‘ūd (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) said: "Shall I tell you what '‘ada' is? It is calumny which is committed among the people."
The Prophet (may Allah's peace and blessings be upon him) wished to warn his nation against calumny and talebearing, which is telling people what others say about them with the intention of causing ill feelings and creating a rift between them. The Prophet (may Allah's peace and blessings be upon him) started his speech with a question in order to grab his listeners' attention. He asked them: "Shall I tell you what '‘ada' is? This term has also been interpreted to mean magic. Then he answered this question saying: "‘Ada" is to circulate the ill-speech that people make against each other. This has the same effect of magic in terms of the corruption and harm it causes among people. It turns people against each other, severs ties that were once strong, and fills the hearts with anger and resentment, as witnessed nowadays.