Al-Dhahabi said the same. Al-Tirmidhi said:

“It is a good, singular hadith. Hardly anyone traces it back through a connected chain other than Jarir ibn Hazim. This hadith has only been narrated from al-Zuhri, from the Prophet, as a mursal report. However, Hibban ibn Ali al-Anazi narrated it from Uqayl, from al-Zuhri, from Ubayd Allah, from Ibn Abbas, from the Prophet; and al-Layth ibn Sad narrated it from Uqayl, from al-Zuhri, from the Prophet, as a mursal report.”

I say: Jarir ibn Hazim was trustworthy, and both Shaykhs relied upon him. He narrated it with a connected chain, and this is an addition that must be accepted. It is not impaired by the narration of those who stopped it at al-Zuhri. For this reason, Ibn al-Qattan said, as cited in al-Fayd: “This is not a hidden defect; therefore, its authenticity is more likely.” Hibban ibn Ali al-Anazi also corroborated him in narrating it with a connected chain, as al-Tirmidhi mentioned.

Luwayn likewise narrated it with a connected chain in his Hadith collection (fol. 2/2), saying: Hibban ibn Ali narrated it to us in this manner. Ibn Adi likewise narrated it with a connected chain (108/1) through another route from him. Al-Tahawi recorded it in al-Mushkil (1/238) through al-Nasai’s route from him. Al-Darimi (2/215) recorded it as follows: Muhammad ibn al-Salt narrated to us; Hibban ibn Ali narrated to us, from Yunus and Uqayl, from Ibn Shihab, from Ubayd Allah ibn Abd Allah, from Ibn Abbas, attributing it to the Prophet, with a similar report, worded: “Whenever they reached twelve thousand, remained steadfast, and were sincere, they prevailed despite their small numbers.”