Sayyiduna Abu Umamah (may Allah be pleased with him) narrates this saying of the Prophet (peace and blessings be upon him): "Do not fast on Saturday, except in the case of an obligatory fast. Even if you find nothing but the bark of a tree (on Saturday), break your fast with it (that is, do not fast)."
Al-Tabarani recorded it in al-Mu'jam al-Kabir through Isma'il bin Ayyash from the people of the Hijaz, and this narrator is da'if (weak) in what he narrates from the people of the Hijaz.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصيام / 5198
Hadith Gradingمحدثین:إسناده ضعیف
Hadith Takhrij«اخرجه الطبراني فى المعجم الكبير (7722) ، أخرجه المعجم الكبير للطبراني برقم: 7722»
Kurayb narrates: Some people sent me to Sayyidah Umm Salamah (may Allah be pleased with her) so that I could ask her on which days the Prophet (peace and blessings be upon him) fasted most. Sayyidah Umm Salamah (may Allah be pleased with her) said: "Saturday and Sunday. He used to say: 'These two days are the Eid (days) of the polytheists, and I love to act contrary to them.'"
Al-Tabarani recorded it in al-Mu'jam al-Kabir, and its narrators are thiqat (trustworthy). Ibn Hibban graded it sahih (authentic).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصيام / 5199
Hadith Gradingمحدثین:إسنادہ صحیح
Hadith Takhrij«اخرجه الطبراني فى المعجم الكبير (283/22 و402) ، أخرجه مسند أحمد برقم: 26210، وأخرجه صحيح ابن خزيمة برقم: 2167»
Ubayd al-A'raj narrates: My grandmother told me that she came to the Prophet (peace and blessings be upon him) while the Prophet (peace and blessings be upon him) was having his morning meal; this was on a Saturday. The Prophet (peace and blessings be upon him) said to her: "Come forward and eat." She said: "I am fasting." The Prophet (peace and blessings be upon him) said: "Did you fast yesterday?" She replied: "No." The Prophet (peace and blessings be upon him) said: "Then eat, for the fast of Saturday is neither for you nor against you (that is, there is neither sin nor reward in it)."
(Allamah Haythami says:) I say: A different hadith from this woman about fasting on Saturday is reported in the Sunan.
Ahmad recorded it. Its chain contains Ibn Lahi'ah, and he has been criticised.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصيام / 5200
Hadith Gradingمحدثین:إسناده ضعیف
Hadith Takhrij«اخرجه احمد فى المسند (368/6) ، أخرجه مسند أحمد برقم: 26536»
Umayr bin Jubayr, the freed slave of Kharijah, narrates: The woman who had asked the Prophet (peace and blessings be upon him) about fasting on Saturday told him that she asked the Prophet (peace and blessings be upon him) about it, and the Prophet (peace and blessings be upon him) said: "Nothing will be for you in it, and nothing will be against you (that is, you will get neither reward nor sin)."
Ahmad recorded it. I do not know this man named Umayr.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصيام / 5201
Hadith Gradingمحدثین:إسناده ضعیف
Hadith Takhrij«اخرجه احمد فى المسند (368/6) ، أخرجه مسند أحمد برقم: 26534»