O Changer of the hearts, make my heart firm upon Your religion.
Anas (raḍiy Allāhu ‘anhu) said: “The Messenger of Allah ﷺ would often say [the above]. So I asked: ‘O Messenger of Allah, we believe in you and what you have come with, but do you fear for us?’ He replied: ‘Yes. Indeed the hearts are in between the two Fingers of Allah’s Fingers. He changes them as He wills.”’ (Tirmidhī 3522)
#2
آمَنْتُ بِاللهِ وَرُسُلِهِ
Āmantu bi-llāhi wa rusulih.
I believe in Allah and His Messengers.
The Messenger of Allah ﷺ said: “Shaytān comes to one of you and says: ‘Who created you?’ He replies: ‘Allah.’ Then Shaytān says: ‘Who created Allah?’ If that happens to any one of you, let him say [the above]. Indeed it will go away from him.” (Ahmad 25671)
Huwa-l-Awwalu wa-l-Ākhiru wa-ẓ-Ẓāhiru wa-l-bāṭin, wa Huwa bi-kulli shay’in ‘Alīm.
He is the First and the Last, the Most High and the Most Near. And He is All-Knowing about everything.
Abu Zumayy reported: “I asked Ibn Abbas (radiy Allāhū ‘anhumā): ‘What is this that I am experiencing?’ He answered: ‘What is it?’ I said: ‘By Allah, I cannot talk about it.’ He asked me: ‘Is it something to do with doubt?’ [When answered it was], he smiled and said: ‘No-one was safe from it until Allah revealed:
“If you are in doubt concerning what We revealed unto you [O Prophet], ask those who read the Scripture from before your time. The truth has indeed come to you from your Lord, so be not one of those in doubt.” (10:94)
Ibn Abbas (radiy Allāhū ‘anhumā) told me: ‘If you find any [doubt] within yourself, say: [the above].” (Abū Dāwūd 5110)