Musannaf Ibn Abi Shayba 3:4882

Waki' narrated to us, from Nafi', from Ibn 'Umar, from Ibn Abi Mulaykah, who said: I saw 'Umar ibn 'Abd al-'Aziz praying in the mosque, and a person passed by him, so he glorified Allah (said "SubhanAllah") for him.