Musannaf Ibn Abi Shayba 21:357

'Affan narrated to us, Aban ibn Yazid al-'Attar narrated to us, Qatada narrated to us, he said: Abu al-'Aliya al-Riyahi narrated the hadith of Suhayl ibn Hanzala al-'Abshami, that he said: No people ever gathered remembering Allah, except that a caller from the sky called out: "Rise, you have been forgiven; your evil deeds have been replaced with good deeds."