I asked Fadala bin Ubayd about hanging the hand around the neck of a thief, whether it was from the Sunnah. He said, "A thief was brought to the Messenger of Allah ﷺ, and his hand was cut off, then he ordered that it be hung around his neck."
حدثنا قتيبة حدثنا عمر بن علي المقدمي حدثنا الحجاج عن مكحول
سألت فضالة بن عبيد عن تعليق اليد في عنق السارق أمن السنة هو قال أتي رسول الله ﷺ بسارق فقطعت يده ثم أمر بها فعلقت في عنقه
[Its chain is daif]. Abu Dawud also reported it in the Book of Hudud, chapter on hanging the hand of the thief around his neck, hadith 4411, from Qutayba with the same chain. Nasai said, 8/92, hadith 4986, Hajjaj bin Artah is daif, his hadith is not to be relied upon, he is a mudallis, and he narrated using an ambiguous form of transmission (ana'a).