Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) says: the Prophet (peace and blessings be upon him) used to fast on Mondays and Thursdays.
Al-Tabarani recorded it in al-Mu'jam al-Kabir. Its chain contains Abu Bilal al-Ash'ari, and he is da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصيام / 5196
Hadith Gradingمحدثین:إسناده ضعیف
Hadith Takhrij«اخرجه الطبراني فى المعجم الكبير (10233)»