Abū Zurʿah was asked about it and said: “It is Ṭalḥah, from ʿAṭāʾ, as a mursal report.”
I say: This Ṭalḥah is abandoned. Strangely, al-Suyūṭī, in al-Laʾāliʾ, found this route only through Ibn al-Najjār. Yet he mentioned a good mursal corroborating report for it, saying: “Ibn Abī ʿAmr said in his Musnad: Bishr ibn al-Sarī related to us: Hammām related to us, from Yaḥyā ibn Abī Kathīr, from Abū Salamah, from al-Ḥaḍramī ibn Lāḥiq, that the Prophet, peace and blessings be upon him, said: ‘When you dispatch a courier ...’”
I say: This is an authentic mursal chain of transmission. Al-Ḥaḍramī ibn Lāḥiq was a younger Successor. He narrated from Ibn ʿAbbās and Ibn ʿAmr without having met them, and there is no harm in him, as Ibn Maʿīn said. Ibn Qutaybah also narrated it through his route in Gharīb al-Ḥadīth (1/46/2).
In sum, the hadith is authentic through these routes, especially since the first route is authentic in itself. Al-Suyūṭī inclined to this view, saying at the end of his discussion: “Al-Ḥākim said in al-Mustadrak: ‘When the narrations concerning a hadith are numerous, it becomes clear that the hadith has an origin.’ And Allah knows best.” He also mentioned a corroborating report from the hadith of Abū Umāmah, attributed to the Prophet, with the wording: “Whenever he dispatched a party, he would say to its commander: ‘When you send a courier to me, make him well-built, handsome, and good-looking.’” Al-Kharāʾiṭī recorded it in Iʿtilāl al-Qulūb: ʿAlī ibn Ḥarb al-Ṭāʾī related to us; my father related to us; ʿAfīf ibn Sālim related to us, from al-Ḥasan ibn Dīnār, from him.
I say: Regarding al-Ḥasan ibn Dīnār, Abū Ḥātim and others said: “A liar.” Thus, no corroboration may be sought from someone like him—far from it. Moreover, he did not meet a single one of the Companions; rather, they only mentioned reports from him from some of the Successors, such as Ibn Sīrīn and others.