سورة Al-Maidah ( The Table spread with Food ) - الآية 107

Then if it is later known that both of them committed sin, two others may take their place, from those who were caused the most harm by the false testimony, and they must swear by Allah that, “Our testimony is more accurate than the testimony of these two, and we have not exceeded the limits – if we do, then surely we shall be of the unjust.”