People complained about Ali. The Messenger of Allah ﷺ then stood among us delivering a sermon, and I heard him say, "People, do not complain about Ali. By Allah, he is indeed stern when it comes to the cause of Allah," or "in the path of Allah."
اشتكى عليا الناس، قال: فقام رسول الله ﷺ فينا خطيبا، فسمعته يقول: أيها الناس لا تشكوا عليا، فوالله إنه لأخيشن في ذات الله أو في سبيل الله.
Imam Ahmad narrated it (11817), and from his route Hakim narrated it (1/68), from Yaqub (that is, the son of Ibrahim bin Saad bin Ibrahim Zuhri), who said, my father narrated to me, from Ibn Ishaq, who said, Abdullah bin Abdul-Rahman bin Muammar bin Hazm narrated to me, from Sulayman bin Muhammad bin Kaab bin Ujra, from his paternal aunt Zaynab bint Kaab, who was married to Abu Saeed Khudri, from Abu Saeed Khudri, who said, then he mentioned it.Hakim said, "This is a hadith sahih in isnad, though the two of them did not include it."Its isnad is hasan because of Zaynab bint Kaab bin Ujra, the wife of Abu Saeed Khudri. There is disagreement about whether she was a companion. Two of her nephews narrated from her, Sulayman bin Muhammad bin Kaab and Saad bin Ishaq bin Kaab. Ibn Hibban mentioned her among the trustworthy narrators, and nothing in her hadith is objectionable, so a narrator like her may have her hadith graded hasan, and this is one such case.Haythami said in al-Majma (9/129), "Ahmad narrated it, and its narrators are trustworthy."