Umm Salamah (RAA) narrated, The Messenger of Allah ( صلی اللہ علیہ وسلم ) used to fast more often on Saturdays and Sundays than on the other days. He would say, "They are the 'ids of the polytheists, and I love to act contrary to what they do." Related by An-Nasal and was rendered authentic by Ibn Khuzaimah, and the wording is his.