Imam Tajud-Din As-Subki in his Tabaqat reports the following beneath his entry on Abi Ibrahim Isma’il ibn Yahya Al-Muzani:
“And Al-Muzani reported from Imam Ash-Shafi’i that he heard him saying, ‘It is not permitted (لا يحل) for anyone who hears the the hadith of Rasulullah (‘alayhis salam) regarding raising the hands at the beginning of Salah, upon bowing, upon rising from bowing to abandon his [exemplary] model of his actions.”