Musnad Ahmad 30:2238

'Affan narrated to us, he said: Hammad ibn Salamah narrated to us, he said: Suhayl ibn Abi Salih informed us, from 'Abdullah ibn Dinar, from Abu Salih, from Abu Hurayrah, that the Messenger of Allah (may Allah bless him and grant him peace) said: "Faith consists of seventy-odd branches. The best of them is 'There is no god but Allah,' and the lowest of them is removing a bone from the road. And modesty is a branch of faith."