The Messenger of Allah ﷺ said, "Do not begin the month until you see the new moon or complete the count of thirty days. Then fast until you see the new moon or complete the count."
قال رسول الله ﷺ: لا تقدموا الشهر حتى تروا الهلال، أو تكملوا العدة، ثم صوموا حتى تروا الهلال أو تكملوا العدة.
It was narrated by Abu Dawud (2326), Nasai (2126), Ibn Khuzayma (1911), Ibn Hibban (3458), Daraqutni (2166), and Imam Ahmad (18825), all of them through Jareer bin Abdul-Hameed Dabbi, from Mansur, from Rabi bin Harash, from Huzaifa, and he mentioned it. Its chain of transmission is sahih. Abu Dawud said, "Sufyan and others narrated it from Mansur, from Rabi, from a man among the companions of the Prophet ﷺ, without naming Huzaifa."I say, Nasai (2127) and Abdul-Razzaq (7337) and others likewise narrated it from Sufyan Thawri, and neither of them mentioned Huzaifa. This does not harm the soundness of the hadith, for it is connected and sahih whether the name of the companion is mentioned or not, since the anonymity of the companions does not detract from the soundness of the hadith.As for the disconnected narration of Hajjaj bin Artah from Mansur, from Rabi, who said, "The Messenger of Allah ﷺ said," it cannot stand against the one who narrated it as connected, because there is well known criticism of Hajjaj bin Artah. It was narrated through his route by Nasai (2128) and Daraqutni (2165).Nasai said, as recorded in Tuhfat Ashraf (283), "I do not know of anyone among the companions of Mansur who said in this hadith, 'from Huzaifa,' other than Jareer, and Hajjaj is daif, no argument can be established by him." I did not find this statement of Nasai's in either Sunan al-Kubra or Sunan Sughra.Bayhaqi said (4/208), "Jareer connected it from Mansur by mentioning Huzaifa in it, and he is trustworthy and authoritative. Thawri and a group of others narrated it from Mansur, from Rabi, from some of the companions of the Prophet ﷺ, from the Prophet ﷺ."