Hisham bin Abi 'Abdullah al-Dastawa'i هشام بن أبي عبد الله الدستوائي · The Chapters on Rulings

“The Testimony of a man or woman who is treacherous, or of one who has been subjected to one of the Haad punishments of Islam, or of one who bears a grudge against his brother, is not permissible.”