Musannaf Ibn Abi Shayba 21:304

Muhammad ibn Bishr and Abu Usamah narrated to us, from Mis'ar, from 'Amr ibn Murrah, from Mus'ab ibn Sa'd, who said: When the servant says, "Subhan Allah" (Glory be to Allah), the angels say, "Wa bi-hamdihi" (And with His praise). When he says, "Subhan Allah wa bi-hamdihi" (Glory be to Allah and with His praise), they pray for him. Abu Usamah said: "They pray for him."