I say: Isḥāq and Bakr are not known for anything other than this single report.
Al-Ḥāfiẓ, in his biographical note on the same Isḥāq, writes: “His status is unknown (majhūl al-ḥāl).” A narrator of unknown status can never be cited as proof.
With regard to the time of the ʿĪd prayer he said: “It was transmitted by Aḥmad ibn Ḥasan al-Bannāʾ on the authority of Jundub, who said: ‘The Prophet ﷺ used to lead us in the Fiṭr prayer when the sun was two spear-lengths above the horizon, and in the Aḍḥā prayer when it was one spear-length above.’ Al-Shawkānī remarked, ‘This is the best ḥadīth that has come down specifying the time of the ʿĪd prayer.’”
I reply: Yes—were it not that the report is unsound. Al-Shawkānī quoted it from al-Ḥāfiẓ’s Talkhīṣ al-Ḥabīr and then stated (3/248), “He offered no commentary on it.”
I say: Yet he supplied enough of its chain for anyone skilled in this discipline to judge its soundness or weakness. I had already cited it from him in Irwāʾ (3/101) and added: “But al-Muʿallā ibn Hilāl appears in its isnād, and the critics are unanimous in declaring him a fabricator, as al-Ḥāfiẓ affirms in his Taqrīb.”
Furthermore, the name of al-Bannāʾ, the transmitter, was inverted by al-Shawkānī; thus, as you see, he wrote “Aḥmad ibn Ḥasan,” and the author followed him. The correct form is Ḥasan ibn Aḥmad, as in the Talkhīṣ (2/83) and in the biographical works. He was a Ḥanbalī jurist, favorably profiled in Shadharāt al-Dhahab, and he died in 471 AH.