ʿAffān, in his version, said: “Abū al-Zubayr informed us,” whereas ʿAbd al-Ṣamad, in his version, said: “Abū al-Zubayr narrated to us,” from Jābir ibn ʿAbd Allāh, that the Messenger of Allah, peace and blessings be upon him, said—and he mentioned it. He added:
“He then said to his Companions: ‘What if we were to remain in Medina, so that, if they entered upon us there, we would fight them?’ They said: ‘O Messenger of Allah, by Allah, no one entered upon us there during the pre-Islamic period; so how could they enter upon us there in Islam?’ ʿAffān said in his version: He said, ‘It is up to you, then.’ He then donned his armour. The Anṣār said, ‘We have caused the Messenger of Allah, peace and blessings be upon him, to abandon his own view.’ So they came and said, ‘O Prophet of Allah, it is up to you, then.’ He said: ‘Once a prophet has donned his armour, it is not for him to remove it until he fights.’”
Ibn Saʿd also narrated it (2/45): “ʿAffān ibn Muslim informed us,” with the same chain, except that he said: “from Abū al-Zubayr, from Jābir.” Al-Dārimī also narrated it (2/129): Al-Ḥajjāj ibn Minḥāl informed us; Ḥammād ibn Salamah narrated to us; Abū al-Zubayr narrated to us from Jābir.
I say: This is a chain of transmission whose narrators are trustworthy according to Muslim’s criteria. However, Abū al-Zubayr practised tadlīs and used the ambiguous “from” transmission formula in all the versions recorded by its transmitters. Al-Ḥāfiẓ’s statement in al-Fatḥ (12/355), “In one narration of Aḥmad: ‘Jābir narrated to us,’” seems to me to be an error on his part, caused by his attention shifting to Ḥammād’s wording in ʿAbd al-Ṣamad’s narration from him—“he narrated to us”—whereupon he assumed that it was Abū al-Zubayr’s wording. Allah knows best.
However, the hadith under discussion has a supporting report, abbreviated and similar in meaning, from Abū Mūsā al-Ashʿarī, in one of his hadiths. After the words, “By Allah, it is good,” it states: “Then they were the group of believers on the Day of Uḥud, and the good was the good that Allah brought thereafter.” It was narrated by al-Bukhārī (12/354–355, al-Fatḥ), Muslim (7/57), and al-Dārimī.
There is another supporting report from Ibn ʿAbbās, similar to it, with the addition after the words, “By Allah, it is good”: “And it came to pass as the Messenger of Allah, peace and blessings be upon him, had said.” It also states that the dream occurred on the Day of Uḥud. Aḥmad narrated it (1/271) with a good chain of transmission.