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. (Using translation from Abū Dāʾūd 3601)
قَالَ رَسُولُ اللهِ ﷺ لَا تَجُوزُ شَهَادَةُ خَائِنٍ وَلَا خَائِنَةٍ وَلَا زَانٍ وَلَا زَانِيَةٍ وَلَا ذِي غِمْرٍ عَلَى أَخِيهِ زَادَ أَبُو عَبْدِ اللهِ فِي رِوَايَتِهِ فِي الْإِسْلَامِ