مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3074
Musnad of 'Abdullah bin al-'Abbas bin 'Abdul-Muttalib from the Prophet
It was narrated from al-Hakam bin Meena' that he heard (from) 'Abdullah bin 'Umar and 'Abdullah bin ‘Abbas (that) they heard The Messenger of Allah (ﷺ) say, on the planks of his minbar: "People must cease neglecting Jumu’ah, or Allah will put a seal over their hearts and they will be recorded among the negligent."
Musnad Ahmad 3099A saheeh hadeeth]