Sayyiduna Abu Hurayrah (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) said: "After faith in Allah Almighty, the greatest wisdom is treating people with affection."
Al-Bazzar recorded it. Its chain contains a narrator Ubaydullah bin Amr (the narrator is unsure; perhaps the words are:) Ubaydullah bin Umar al-Qaysi, who is da'if (weak). The hadith of Sayyiduna Ali (may Allah be pleased with him) will come later in the chapter on intellect.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الأدب / 12634
Hadith Gradingمحدثین:إسنادہ ضعیف
Hadith Takhrij«اخرجه البزار فى المسند (1945) ، أخرجه المعجم الأوسط للطبراني برقم: 6740»