Question
Is this report reliable ?
أكمل المؤمنين إيمانا وأفضل المؤمنين إيمانا أحسنهم خلقا
(مصنف)
Translation
The most complete of believers and the best of believers are those with the best character (Musannaf)
Answer
This Hadith has been recorded in numerous Hadith collections with similar wordings, other than the source you have cited. Imams Tirmidhi, Ibn Hibban and Hakim (rahimahumullah) have declared the Hadith as authentic (sahih).
(Sunan Tirmidhi, Hadith: 1162, Sahih Ibn Hibban; Al Ihsan, Hadith: 479 and Mustadrak Hakim, vol. 1, pg. 3)
And Allah Ta’ala Knows best
Answered by: Mawlana Suhail Motala
Approved by: Mawlana Muhammad Abasoomar
Checked by: Mawlana Haroon Abasoomar