From Saalih bin ad-Darees who said:
Abdullaah began beating the head of a relative of his who held the view of Jahm. So I saw him beating him on his head with a sandal whilst saying, "No (I will not stop), (not) until you say Ar-Rahmaan ascended above the Throne, separate and distinct from His creation (ar-Rahmaanu 'alal-arsh istawaa, baa'inun min khalqihi)."
Source: "Mukhtasar al-Uluww" of adh-Dhahabee, (p. 172)