the believers will rejoice in Allah’s victory.”
And He, Exalted is He, says:
“We have appointed only angels as keepers of the Fire, and have made their number only a trial for those who disbelieve, so that those given the Scripture may become certain and those who believe may increase in faith.”
And He says:
“It is He who sent down tranquility into the hearts of the believers so that they might increase in faith alongside their existing faith.”
This verse was revealed when the Prophet, may Allah bless him and grant him peace, and his Companions returned from al-Hudaybiyyah. Thus He made tranquility a cause of increased faith. Tranquility is reassurance within the heart, distinct from the heart’s knowledge and assent. Hence He said concerning the day of Hunayn:
“Then Allah sent down His tranquility upon His Messenger and upon the believers, and sent down forces you did not see.”
And He, Exalted is He, says:
“As one of two, when they were in the cave, he said to his companion, ‘Do not grieve; indeed, Allah is with us.’ Then Allah sent down His tranquility upon him and supported him with forces you did not see.”
No Quranic revelation had come down on the day of Hunayn or on the day in the cave. Rather, He sent down His tranquility and reassurance in the face of fear of the enemy. Thus, when He sent down tranquility into their hearts upon their return from al-Hudaybiyyah, so that they might increase in faith alongside their existing faith, this indicated that the additional faith was a state, quality, and action of the heart, such as its reassurance, calm, and certainty.
Certainty may relate to action and reassurance, just as it may relate to knowledge. Likewise, the doubt that contradicts certainty may concern knowledge or the heart’s reassurance. Hence the transmitted supplication says:
“O Allah, grant us such fear of You as will stand between us and disobedience to You; such obedience to You as will bring us to Your Paradise; and such certainty as will ease for us the calamities of this world.”
In the hadith of al-Siddīq, reported by Ahmad, al-Tirmidhī, and others from the Prophet, may Allah bless him and grant him peace, he said:
“Ask Allah for well-being and certainty, for after certainty no one has been given anything