Reference: Musnad of Imaam Ahmad v3 p198; at-Tirmidhee – The Book of the description of the Day of Judgement, v4 p569, Number 2499. Ibn Maajah – The Book of Abstention, Chapter – The mention of repentance. ad-Daarimee – The Book of ar-Riqaaq, Chapter – Repentance. Sharhus-Sunnah of al-Baghawee v5 p92. Hilyatul-Awliyaa wa-Tabaqaat al-Asfiyaa of Abu N’aeem v6 p332. Kashful-Khafaa of al-Ajloonee v2 p120. al-Mustadrak of al-Haakim v4 p273, where it mentions: This hadeeth has a sound chain of narrators and they (al-Bukhaaree and Muslim) have not transmitted it. Sharhus-Sunnah of al-Baghawee v2 p120 where it mentions: Its chain of narrators is strong.
said:
All of the children of Aadam make mistakes, and the best of them are those who repent.
