Muwatta Malik 1640

Arabic

وَحَدَّثَنِي عَنْ مَالِكٍ، أَنَّهُ قَدْ بَلَغَهُ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏ "‏ بُعِثْتُ لأُتَمِّمَ حُسْنَ الأَخْلاَقِ ‏"‏ ‏.‏

Translation

Yahya related to me from Malik that he had heard that the Messenger of Allah, may Allah bless him and grant him peace, said, "I was sent to perfect good character

Authenticity

Sahih · Salim al-Hilali

Reference