What are the traditional books in the various fields of religious knowledge for the pure Sunnis who were not known for innovation, and what is the reason for later generations adopting books by innovators who went astray in matters of creed and other areas? Is it permissible to ask for Allah's mercy upon them, such as Al-Izz ibn Abd al-Salam and Ibn al-Arabi?

The books of the People of Sunnah, Hadith, and Athar in Tafsir (exegesis), Hadith, Aqeedah (creed), Fiqh (jurisprudence), and language are numerous, such as Sahih al-Bukhari, Tafsir al-Tabari, and Al-Sunnah by Al-Khallal. As for the groups that deviate from the Pious Predecessors, such as the Jahmiyyah, Mu'tazilah, and Ash'aris, it is permissible to pray for mercy upon the people of non-disbelieving innovations, as they are Muslims. There is no absolute obligation to abandon their books. Abandonment may serve as a means of rebuke and discipline, but its benefit may cease if it does not lead to deterrence, and instead leads to the nullification of good deeds. What conforms to the Sunnah should be taken from them and utilized, while caution must be exercised regarding what contradicts it. Imam Ibn al-Arabi and Ibn Abd al-Salam are two great scholars with beneficial works. Their books can be benefited from, while being cautious of what in them contradicts the Salafi principles. One must busy oneself with seeking knowledge from trustworthy individuals and avoid delving into sects and schools of thought if one is not qualified to do so.