question #3 Sahih Muslim 677j, Book 5, Hadith 387 : Why might the Prophet Muhammad (ﷺ) choose to abandon a specific supplication after a period of time?

Anas reported that the Messenger of Allah (ﷺ) observed Qunut for one month invoking curse upon some tribes of Arabia (those who were responsible for the murders in Bi’r Ma’una and Raji’), but then abandoned it.