Narrated Ibn 'Abbas:The Prophet (ﷺ) as saying: Seek laitat al-Qadr in the last ten night of Ramadan. When nine (nights) remain (i.e. on the twenty first) , when seven (night) remain (i.e. on the twenty third), and when five (nights) remain (i.e. on the twenty fifth)

English translation · Sunan Abu Dawud