Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) said: In this Ummah it is not lawful (when carrying out punishment) to strip (the offender), stretch him out, put him in an iron collar, or bind him in fetters.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الأشربة والحد فيها / 17577