Musnad Ahmad 534:18

'Isam ibn Khalid narrated to us, he said: Abu 'Abd Allah al-Hasan ibn Ayyub al-Hadrami narrated to us, he said: 'Abd Allah ibn Busr showed me a mole on his head, so I placed my finger upon it. He said: "The Messenger of Allah, peace and blessings of Allah be upon him, placed his finger upon it, then said: 'You shall surely reach a generation (qarn).'" Abu 'Abd Allah said: "And he had a thick head of hair (jummah)."