Abu Said, or Abu Hurairah, reported that the Messenger of Allah ﷺ said, "When three people set out on a journey, they should appoint one of them as their leader."
أو أبي هريرة أن رسول الله ﷺ قال: إذا خرج ثلاثة في سفر فليؤمروا أحدهم.
Abu Dawud (2608, 2609) narrated it from Ali bin Bahr, who said, Hatim bin Ismail told us, Muhammad bin Ajlan told us, from Nafi, from Abu Salama, from Abu Hurairah, who related it. Its chain is hasan because of the discussion surrounding Muhammad bin Ajlan, though he is hasan al-hadith. The uncertainty between the two companions does not affect the soundness of the hadith. Likewise, it is not harmed by what Bazzar (5850) narrated from the hadith of Hatim bin Ismail, from Muhammad bin Ajlan, from Nafi, from Nafi, from Ibn Umar, relating something similar.The meaning of the hadith is supported by what Umar bin Khattab narrated, who said, "If you are three on a journey, appoint one of you as leader, that is a leadership the Messenger of Allah ﷺ commanded." So the correct view is that it is mawquf. Bazzar (329) narrated it from Ammar bin Khalid Wasiti, who said, Qasim bin Malik Muzani told us, Amash told us, from Zayd bin Wahb, from Umar bin Khattab, who related it. Bazzar commented afterward, "This hadith has been narrated by more than one person from Amash, from Zayd bin Wahb, from Umar, as mawquf, and we do not know of anyone who made it marfu except Qasim bin Malik, from Amash."Daraqutni, in Ilal (2/151), judged it correct that it is the statement of Umar. This is likewise supported by the statement of Ibn Masud, "If you are three on a journey, appoint one of you as leader, and let two of you not whisper together apart from their companion." Tabarani narrated it in al-Kabir (9/208), and Tahawi in Sharh Mushkil (1792), and Sarraj in his Hadith (1250), all through the route of Shuba, from Abu Ishaq, from Abu Ahwas, from Abdullah bin Masud, who related it. Its chain is sahih.Once this is known, it is not harmed by what has been used to criticize the hadith of Abu Hurairah and Abu Saeed Khudri, namely that Musaddad narrated it, as mentioned in Ithaf Khayra (5724), through the route of Ibn Ajlan, from Ibn Ajlan, from Nafi, from Abu Salama, as a mursal narration. Abu Zuraa (225) and Daraqutni (326) both affirmed that it is sahih as a mursal narration. Muhammad bin Ajlan has a slight weakness, and this difference traces back to him, so between his narrating it as connected and as mursal, the ruling goes to the connected version based on the meaning, while the ruling goes to the mursal version based on the technical craft of hadith criticism, as Abu Hatim and Daraqutni stated.