From Sahih Muslim (Hadith 1547):
Anas b. Malik reported:The Messenger of Allah (ﷺ) observed Qunut for a month in the dawn prayer after ruku' and invoked curse upon Ri'l, Dhakwan, and said that 'Usayya had disobeyed Allah and His Apostle (ﷺ)
Reference: Muslim 1547