Weak
graded by Salim al-Hilali
Muwatta Malik 224
وَحَدَّثَنِي عَنْ مَالِكٍ، أَنَّهُ بَلَغَهُ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ
" إِنِّي لأَنْسَى أَوْ أُنَسَّى لأَسُنَّ "
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 forget or I am made to forget so that I may establish the sunna."
Reported by Malik (No. 224).