[8] During "a life of great intellectual, religious and political activity,"[8] Ibn al-Jawzi came to be widely admired by his fellow Hanbalis for the tireless role he played in ensuring that that particular school – historically, the smallest of the four principal Sunni schools of law – enjoy the same level of "prestige" often bestowed by rulers on the Maliki, Shafi'i, and Hanafi rites.

[10] In the vast majority of the public sermons delivered during al-Mustadi's reign, Ibn al-Jawzi often presented a stanch defense of the prophet Muhammad's example, and vigorously criticized all those whom he considered to be schismatics in the faith.

[10] At the same time, Ibn al-Jawzi's reputation as a scholar continued to grow due to the substantial role he played in managing many of the most important universities in the area,[10] as well as on account of the sheer number of works he wrote during this period.

[8] As scholars have noted, Ibn al-Jawzi's prodigious corpus, "varying in length" as it does,[8] touches upon virtually "all the great disciplines" of classical Islamic study.

[13] In these sermons, Ibn al-Jawzi is said to have "vigorously defended the prophetic precedent and criticized, not only all those whom he considered to be schismatics, but also the jurists who were too blindly attached to their own schools of law.

[8] It was at this time that he told al-Mustadi to engrave an inscription onto the widely venerated tomb of Ibn Hanbal (d. 855) – the revered founder of the Hanbali rite – which referred to the famed jurist as "Imām.

[8] Although the reasons for the matter remain unclear in the historical record,[8] al-Nasir eventually sentenced Ibn al-Jawzi to live under house arrest for five years.

[8] One of the possible reasons for this may be that Ibn al-Jawzi's relationship with the caliph had soured after the scholar had written a direct refutation of the ruler's policy in a particular matter.

[8] While Ibn al-Jawzi did criticize charlatans who masquerade as holy men, he unreservedly states that true "saints do not violate" orthodox belief, practice, and law.

[19] Regarding saints, Ibn al-Jawzi said: The saints and the righteous are the very purpose of all that exists (al-awliya wa-al-salihun hum al-maqsud min al-kawn): they are those who learned and practiced with the reality of knowledge... Those who practice what they know, do with little in the world, seek the next world, remain ready to leave from one to the other with wakeful eyes and good provision, as opposed to those renowned purely for their knowledge.

As has been noted by scholars, his Talbīs Iblīs, which criticizes innovations in all the major Islamic sciences including tafsir and fiqh, is by no means a rejection of Sufism as a whole.

[21] Ibn al-Ahdal [ar] (d. 855/1451) in his Kashf al-Ghata' 'an Haqa'iq al-Tawhid (Arabic: كشف الغطاء عن حقائق التوحيد) considered him one of the Ash'ari scholars along with Abdul Qadir Gilani.

"[22] And he continued his attack on Abu Ya'la by stating that, "Whoever confirms that God has molars as a divine attribute, has absolutely no knowledge of Islam.

"[23] Ibn al-Jawzi's most famous work in this regard is his Bāz al‐ašhab al‐munqadd 'alà muhālifī al‐madhab (The Gray Falcon Which Attacks the Offenders of the [Hanbalī] School).

Ibn al-Jawzi's work focused primarily on diet and natural remedies for both serious ailments such as rabies and smallpox and simple conditions such as headaches and nosebleeds.