Saying of Someone: “His Heart Is Full of Kufr”

Question

If someone, out of personal anger, says of another, “His heart is full of kufr,” what is the ruling on such a person?

Answer

To say of someone that his heart is full of kufr is a very grave and dangerous utterance; it should by no means be said. The state of the heart is known to none but Allah. Revelation used to come to the Prophet ﷺ, and he was informed about certain persons, so at times he would even make it known; today no one has that right.

Source: Fatawa Mahmudiyya

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