Makhul (RAA) narrated, ‘The Messenger of Allah ( صلی اللہ علیہ وسلم ) set up the ballista while attacking the people of at-Ta’if`.’ Related by Abu Dawud with a trustworthy chain of narrators, but it is hadith Mursal. Al-'Uqayli connected it (to the Prophet ( صلی اللہ علیہ وسلم )) with a weak chain narrated by Ali (ra).