Abu Dawud said: It has also been transmitted by Ibn Al 'Arubah from Qatadah from the Prophet (ﷺ) to the effect that he gave a beating forty times with palm branches and sandals. And Shu'bah narrated it from Qatadah on the authority of Anas from Prophet (ﷺ). This version has: He gave a beating with two palm-branches about forty times.
In-book : Book 40, Hadith 129
English translation : Book 39, Hadith 4464