47:(29-31)

Or do those in whose hearts is disease think that Allah would never expose their [feelings of] hatred? And if We willed, We could show them to you, and you would know them by their mark; but you will surely know them by the tone of [their] speech. And Allah knows your deeds. And We will surely test you until We make evident those who strive among you [for the cause of Allah ] and the patient, and We will test your affairs.