Musannaf Ibn Abi Shayba 21:609

Abu Khalid al-Ahmar narrated to us, from Ibn ‘Ajlan, from ‘Abd al-Jalil, from Khalid ibn Abi ‘Imran, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Take your shield." They said: "O Messenger of Allah, is it against an enemy that has arrived?" He said: "No, rather it is against the Fire." We said: "What is our shield against the Fire?" He said: "Subhan Allah (Glory be to Allah), wal-hamdu lillah (and praise be to Allah), wa la ilaha illallah (and there is no god but Allah), wallahu akbar (and Allah is the Greatest). For they will come on the Day of Resurrection as those that precede, those that follow, and those that flank, and they are the enduring righteous deeds."