Sahih Bukhari
Prayers (Salat)
Volume: 001 / Book Number: 008 / Hadith Number: 372
Narrated 'Uqba bin 'Amir:
The Prophet was given a silken Farruj as a present. He wore it while praying. When he had finished his prayer, he took it off violently as if with a strong aversion to it and said, "It is not the dress of Allah-fearing pious people."