Sunan Ibn Majah 794
سنن ابن ماجه#794SahihIbn 'Abbas and Ibn 'Umar narrated that:They heard the Prophet say on his pulpit: "People should desist from failing to attend the congregations, otherwise Allah will seal their hearts, and they will be among the negligent
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Fouad Abd al-BaqiSahih
Shuaib Al ArnautSahih
Zubair Ali ZaiSahih Muslim
In-book reference: 4:60