Musannaf Ibn Abi Shayba 3:6472

Waki’ narrated to us, from Sufyan, from Mansur, from Ibrahim, who said: There are five things the Imam keeps silent (does not recite aloud): Seeking refuge with Allah (Ta’awwudh), and "Glory be to You, O Allah, and with Your praise" (Subhanaka Allahumma wa bihamdika), and "In the name of Allah, the Most Gracious, the Most Merciful" (Bismillah al-Rahman al-Rahim), and "Amen" (Amin), and "O Allah, our Lord, to You is the praise" (Allahumma Rabbana laka al-hamd).