مُسْنَدُ أَحْمَدَ
Musnad Ahmad 2132
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated from Ibn 'Abbas (رضي الله عنه) that the Prophet (ﷺ) said: "Teach and make things easy; do not make things difficult. If one of you gets angry, let him keep quiet.”
Musnad Ahmad 2136Hasan because of corroborating evidence; this is a da'eef is