The Shaykh's advice to read al-Shatibi's book al-I'tisam and Ibn Taymiyyah's book Iqtida' al-Sirat al-Mustaqim: Refuting the People of the Blazing Fire, in the chapter on religious innovations and their criteria

The Shaykh : And before I mention what I know on this matter, I want to advise you, in your capacity as students of knowledge like me, to study this specific issue so that you understand it correctly and so that you may be like the righteous Salaf in their avoidance of religious innovation, even if that innovation is based on a general text from the hadiths of the Messenger of Allah (peace and blessings be upon him), so that you do not fall into religious innovation. I advise you to read a book that is the greatest book I have known on this subject, which is the book "al-I'tisam" by Imam al-Shatibi (may Allah have mercy on him). This book is dedicated to this subject; I know of no equivalent to it. Everyone who came after him is merely dependent on it and draws from it. Otherwise, there is a specific section that you must also read by Shaykh al-Islam Ibn Taymiyyah (may Allah have mercy on him) in his great book "Iqtida' al-Sirat al-Mustaqim: Refuting the People of the Blazing Fire". In this book, Shaykh al-Islam Ibn Taymiyyah addressed this important and serious issue, and in general, he concluded with what is indicated by the aforementioned hadith and those of similar meaning . However, he looked at the issue from another angle, which is that some matters may arise, and the scholars of knowledge may see them as prescribed, yet they did not exist in the time of the Messenger of Allah (peace and blessings be upon him). So how was the rule not applied to them? Meanwhile, many new matters, and very many indeed, occurred, and the scholars of research, such as al-Shatibi, Ibn Taymiyyah, and others, considered these innovations. What is the ruling that distinguishes between what occurs and is prescribed, and what occurs and is not prescribed? This is what Imam al-Shatibi detailed in the aforementioned book al-I'tisam, and Shaykh al-Islam summarized the speech in the book mentioned above. So I will summarize the matter for you. I do not, of course, want to remind you of the texts that confirm this great Islamic rule , because I believe you are aware of them, as I think and hope. But I actually want to clarify two matters for you so that you may verify the meaning of this authentic hadith , so that you do not fall into excess or negligence. Because some people, due to their ignorance of what will be mentioned regarding the two Shaykhs, introduce innovations and cling to them because they fall under general texts, while other people deny matters that have occurred on the pretext that they are innovations, when they are not among the innovations. This precise detail is something we all need.