Muslim, the compilers of the Sunan, al-Bayhaqi (4/207), al-Tayalisi (1/182), and Ahmad (2/234 and 281) recorded it. It also has a corroborating report from Ibn ʿAbbas, documented in al-Irwaʾ (894).

Know that the prohibition against fasting on Saturday—except in the case of an obligatory fast—has been authentically established, and no other exception was made. On its apparent meaning, this conflicts with the preceding permission to fast on Saturday along with fasting on Friday. Thus, either the permission must be given precedence over the prohibition, or the prohibition over the permission. The latter is, in my view, more likely correct. There is not enough room here to explain this; whoever wishes to pursue it should consult my book Tamām al-Minnah: Commentary on Fiqh al-Sunnah (405–408, Amman edition).

2399 — “He prohibited the mahāshī (lower intestinal passages) of women.”

Al-Tabarani recorded it in al-Muʿjam al-Awsat (1/196/1—Zawaʾid al-Muʿjamayn), through ʿAli ibn Bahr, from Ibn Abi Fudayk, from al-Dahhak ibn ʿUthman, from Muhammad ibn al-Munkadir, from Jabir ibn ʿAbd Allah, attributed to the Prophet. He said: “No one narrated it from al-Dahhak except Ibn Abi Fudayk; ʿAli alone reported it.” I say: He was a trustworthy and virtuous narrator, and those above him are trustworthy narrators from Muslim’s transmitters; thus, the chain of transmission is sound and authentic. The hadith also has a corroborating report from ʿUqbah ibn ʿAmir, documented in Adab al-Zifaf (p. 31).

Mahāshī of women: Ibn al-Athir said in al-Nihayah: “This is how it occurs in one narration. It is the plural of mahshāh, referring to the lower portions of the intestines where food collects; it is thus used euphemistically for the anuses.”