As for the hadith reported by al-Khaṭīb from Jābir, it is authentic, and its chain of transmission is good. Its text differs somewhat from this one, however; therefore, I thought it best to document it separately. It is as follows:

815 — “Abū Bakr and ʿUmar are to this religion as hearing and sight are to the head.”

Al-Ṭabarānī and al-Khaṭīb recorded it in The History of Baghdad (8/459–460), through ʿAbd Allāh ibn Muḥammad ibn ʿAqīl, from Jābir ibn ʿAbd Allāh, who said: The Messenger of Allah, peace and blessings be upon him, said it.

I say: This is a good chain of transmission. All of its narrators are trustworthy. Ibn ʿAqīl has been criticized with regard to his memory, but this does not lower his hadith below the rank we have mentioned.

Ibn Shāhīn also recorded it in The Virtues of the Ten Given Glad Tidings of Paradise, from his al-Sunnah (no. 70 in my copy), through two chains from al-Ḥakam ibn Marwān, who said: Furāt ibn al-Sāʾib narrated to us from Maymūn ibn Mihrān, from Ibn ʿUmar:

“The Prophet, peace and blessings be upon him, wished to send a man on an important errand, while Abū Bakr was on his right and ʿUmar on his left. ʿAlī ibn Abī Ṭālib said to him, ‘Would you not send one of these two?’ He replied, …” Then he cited it.

However, this Furāt is abandoned, and thus cannot be used as corroborating evidence.

It has two further supporting narrations, from ʿAmr ibn al-ʿĀṣ and Ḥudhayfah ibn al-Yamān, both recorded by al-Haythamī in Majmaʿ al-Zawāʾid (9/52–53).