I say: This is an authentic chain of transmission, meeting Muslim’s criteria.

A detachment: originally, a division or group of people; and, in military usage, the force stationed behind the army, to which they retreat if they are overcome by fear or defeat, as stated in al-Nihāyah.

1917 — “Fast upon sighting the crescent, and end the fast upon sighting it. If clouds, darkness, or a dust cloud obscure it from you, then complete the prescribed number. Do not anticipate the month, nor precede Ramadan by fasting a day of Shaʿbān.”

Abū ʿUbayd recorded it in Gharīb al-Ḥadīth (59/1–2): Ibn Abī ʿAdī narrated to us, from Ḥātim ibn Abī Ṣaghīrah, from Simāk ibn Ḥarb, from ʿIkrimah, from Ibn ʿAbbās, from the Prophet, with this wording.

I say: This is a sound chain of transmission. All its narrators are trustworthy and are narrators of Muslim, although Simāk has received some slight criticism.

Al-Nasāʾī also recorded it (1/306–307): Qutaybah informed us: Ibn Abī ʿAdī narrated to us with it, but without the words, “or a dust cloud.” Aḥmad likewise recorded it (1/226) through Ismāʿīl ibn Abī ʿUlayyah, who said: Ḥātim ibn Abī Ṣaghīrah informed us with it. He also recorded it (1/258) through Zāʾidah, from Simāk, with similar wording. Al-Bayhaqī likewise recorded it (4/207).

The hadith has other routes from Ibn ʿAbbās and corroborating reports, which I have documented in al-Irwāʾ under hadith 902 and in Ṣaḥīḥ Abī Dāwūd (2015 and 2016).

A dust cloud: haze or dust. The term is also used of fine dust when it rises: habā, yahbū, hubūwwan.

1918 — “Fast from one new moon to the next.”

Al-Ṭabarānī recorded it in al-Awsaṭ (no. 3046): Ibrāhīm—namely, Ibn Hāshim