Sunan an Nasai
4982
Daif+2

It was narrated that Ibn Muhairiz said; "I asked Fadalah bin 'Ubaid about hanging the hand (of the thief) from his neck, and he said:'It is Sunnah. The Messenger of Allah cut off a thief's hand then hung it from his neck."'(Daif)

DaifAbu Ghuddah
DaifAl-Albani