It is narrated from Sayyiduna Anas bin Malik (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Whenever people sit to remember Allah, the Mighty and Majestic, a caller calls out to them from the heaven: 'Rise, you have been forgiven, and your evil deeds have indeed been replaced with good deeds.'"
No one narrated this hadith from Maymun bin Ajlan (may Allah have mercy on him) except Isma'il bin Abd al-Malik (may Allah have mercy on him).
Hadith Referenceالمعجم الأوسط / باب الألف / 1556
Hadith Takhrij«أخرجه الضياء المقدسي فى «الأحاديث المختارة» برقم: 2677، 2678، 2675، 2676، وأحمد فى «مسنده» برقم: 12648، وأبو يعلى فى «مسنده» برقم: 4141، والبزار فى «مسنده» برقم: 6467»