Is the Qunut in Fajr legislated specifically when a calamity (nazilah) afflicts the Muslims?
Chapter on the Times When Prayer is Prohibited
Al-Mughni
Book of Prayer
Primary text
If a calamity afflicts the Muslims, the Imam is permitted to recite the Qunut in the morning prayer, and those praying behind him say 'Amin'. Imam Ahmad explicitly stated this. This ruling aligns with the practice of the Prophet, peace be upon him, who recited Qunut for a month against a specific tribe and then ceased, and with the statement of Ali when he performed Qunut, saying, 'I am only seeking aid against this enemy of ours.' Abu Hanifa and Al-Thawri share this position, restricting the Qunut to such circumstances. The supplication used should resemble what the Prophet and his Companions recited, such as the narration attributed to Umar: 'O Allah, forgive the believing men and women, the Muslim men and women... O Allah, curse the disbelievers among the People of the Book... O Allah, we seek Your aid...'
Supporting text
Abu Al-Khattab opined that Qunut should be recited in both Fajr and Maghrib because they are audible prayers performed at the beginning and end of the day. Another view suggests recitation in all audible prayers by analogy to Fajr, but this is deemed invalid because there is no established report of the Prophet or his Companions performing Qunut in any obligatory prayer besides Fajr and Witr.