Musnad Ahmad 368:1

Rawh and ‘Abd al-Razzaq narrated to us, they said: Ibn Jurayj informed us, he said: Hasan ibn Muslim informed me, from Tawus, from a man who reached the Prophet, may Allah bless him and grant him peace, that the Prophet, may Allah bless him and grant him peace, said: "Tawaf is only a prayer, so when you perform Tawaf, then speak little." And Ibn Bakr did not attribute it to the Prophet (marfu').