رسول الله (صلی الله علیه و آله):
أدنَى الكُفرِ أنْ يَسمعَ الرّجُلُ مِن أخيهِ الكَلِمَةَ فيَحْفَظَها علَيهِ يُريدُ أنْ يَفْضَحَهُ بها، اولئكَ لا خَلاقَ لَهُم.
The Prophet Muhammad (S):
The most basic level of infidelity is for a man to hear a fellow brother say something and memorize it for future to use against him in order to shame him with it. Those are worthless people indeed.