Muwatta Malik, Book 47, Hadith 1646 (In-Book) ⓘ

Malik related to me from Ibn Shihab from Humayd ibn Abd ar-Rahman ibn Awf that a man came to the Messenger of Allah, may Allah bless him and grant him peace, and said, "Messenger of Allah, teach me some words which I can live by. Do not make them too much for me, lest I forget." The Messenger of Allah, may Allah bless him and grant him peace, said, "Do not be angry."

وَحَدَّثَنِي عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، عَنْ حُمَيْدِ بْنِ عَبْدِ الرَّحْمَنِ بْنِ عَوْفٍ، أَنَّ رَجُلاً، أَتَى إِلَى رَسُولِ اللَّهِ صلى الله عليه وسلم فَقَالَ يَا رَسُولَ اللَّهِ عَلِّمْنِي كَلِمَاتٍ أَعِيشُ بِهِنَّ وَلاَ تُكْثِرْ عَلَىَّ فَأَنْسَى ‏.‏ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏ "‏ لاَ تَغْضَبْ ‏" ‏ ‏.‏