What is the ruling on Qunūt in the five obligatory prayers, and did the Prophet, may Allah bless him and grant him peace, supplicate against the Jews for forty days in the five prayers, and what are the evidences for that?

Qunut (supplication) in Dhuhr, Asr, Maghrib, and Isha prayers without a cause is impermissible by scholarly consensus. As for Fajr prayer, there is a difference of opinion. Qunut al-Nawazil (supplication during calamities) in the five prayers is recommended according to the majority of scholars, due to the practice of the Prophet, peace and blessings be upon him. He performed Qunut for a month, supplicating against a tribe of Arabs who had killed the Qurra' (reciters of the Quran), and he performed Qunut supplicating for the deliverance of the weak and oppressed in Mecca. However, his Qunut for forty days against the Jews has no basis.