Muwatta Malik 1640
موطأ مالك#1640Sahihوَحَدَّثَنِي عَنْ مَالِكٍ، أَنَّهُ قَدْ بَلَغَهُ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " بُعِثْتُ لأُتَمِّمَ حُسْنَ الأَخْلاَقِ " .
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
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Salim al-HilaliSahih Lighairihi
In-book reference: 47:8