The Messenger of Allah ﷺ permitted the Mothers of the Believers a hand-span in the length of their hems. They asked him for more, so he added another hand-span, making it a forearm's length. They used to send to us, and we would measure out a forearm's length for them.
حدثنا يحيى عن سفيان حدثني زيد العمى عن أبي الصديق
رخص رسول الله ﷺ لأمهات المؤمنين في الذيل شبرا فاستزدنه فزادهن شبرا آخر فجعلنه ذراعا فكن يرسلن إلينا نذرع لهن ذراعا
Its chain of transmission is sahih. Sufyan is Thawri. Zayd Ammi is Zayd bin Hawari, of Basra, the judge of Herat. Abu Dawud said, he is Zayd bin Murrah, so it appears that Hawari was a title of his father, and this Zayd is trustworthy. Hasan bin Sufyan considered him trustworthy, and Ahmad said, he is decent. Some critics spoke against him and deemed him daif, but Shubah and Sufyan Thawri narrated from him, and the two of them narrate only from trustworthy narrators. Ibn Adi said, most of what he narrates is daif, yet Shubah did narrate from him, and perhaps Shubah did not narrate from anyone weaker than him. Bukhari gave his biography in al-Kabir 3/1/358 and mentioned no criticism of him, which supports that he is trustworthy. Whoever reads his biography in al-Mizan by Dhahabi will be certain that what the hadith scholars objected to in him was actually a defect in those who narrated from him, and for that reason Tirmidhi graded his narration sahih, as I explained in my commentary on it, 1:416.Hawari is with fatha on the ha and the waw, kasra on the ra, and doubling of the ya. Ammi is with fatha on the ayn and doubling of the mim, which carries a kasra. It is said that it is a relation to Amm, a clan of Tamim, and it is also said that whenever he was asked about something he would say, "I will ask my paternal uncle (ammi)." In al-Tahdhib it states that he was a client (mawla) of Ziyad bin Abihi, so it appears the second explanation is more likely correct.Abu Siddiq Naji is Bakr bin Qays, according to what Bukhari asserted definitively in al-Kabir 1/2/93 and what Samani stated in al-Ansab. It is also said that he is Bakr bin Amr, according to what Bukhari relayed from Ahmad and Ishaq. This Abu Siddiq is a trustworthy successor (tabii), deemed trustworthy by Ibn Main, Abu Zura, and others, and the compilers of the six books narrated from him. Naji is a relation to the tribe of Banu Najiyah, as stated in al-Ansab by Samani, folio 550b.This hadith was narrated by Abu Dawud, 4:111, from Musaddad, from Yahya Qattan, with this chain of transmission. Ibn Majah also narrated it, 2:195, through the route of Abdul-Rahman bin Mahdi, from Thawri. Munziri found fault with it because of Zayd Ammi, but you now know the truth regarding him. See also 4489.