The Messenger of Allah ﷺ said: The testimony of a deceitful man or woman, of an adulterer and adulteress, and of one who harbours rancour against his brother is not allowable.
قَالَ رَسُولُ اللَّهِ ﷺ لاَ تَجُوزُ شَهَادَةُ خَائِنٍ وَلاَ خَائِنَةٍ وَلاَ زَانٍ وَلاَ زَانِيَةٍ وَلاَ ذِي غِمْرٍ عَلَى أَخِيهِ