His early life:
I have already highlighted in the beginning of the author’s biography that there is no available full biography for Imam Ath-Thaʿlabiyy, may Allah have mercy upon him. The sources of his biography do not mention anything about his early life or his quest for knowledge. However, when one reads in Ath-Thaʿlabiyy’s Tafsir, he will find some indications that he, may Allah have mercy upon him, grew up in an environment that encouraged knowledge, which is not strange for someone who lived in Naysābūr, the home of knowledge and scholars, and the center of scientific and cultural prosperity in general terms. But more specifically, Abū Isḥāq’s private environment was also an environment of knowledge and scholars. There is nothing to prove that more than the fact that his house, may Allah have mercy upon him, was a garden of knowledge, to which scholars and students of knowledge would come, and where knowledge seminars and lessons would be held as will be explained in the second point. And since Ath-Thaʿlabiyy grew up in an environment where knowledge was cherished, and lived in a house to which teachers of knowledge would come, and in which scholars’ lessons were held, this matter had the greatest impact on Ath-Thaʿlabiyy’s early life and his quest for knowledge, and even his seriousness and diligence in this regard, for a house to which scholars come will definitely be a fertile field for knowledge, and therefore its dweller will be eager for knowledge, keen on learning, and on spending the spring of his life and the vigor of his youth in the company of knowledge and scholars.
Second: His quest for knowledge:
The start:
When one contemplates Tafsir Ath-Thaʿlabiyy, he finds that he, may Allah have mercy upon him, sometimes refers to the date when he attended lectures from some of his shaykhs. And all of these lectures were after the year (380 AH). He narrated on the authority of his two shaykhs Ibn Al-Muqriʾ and Ibn Mahrān who died in the year (381 AH) as previously mentioned when talking about his birth
With the previous two facts:
A- The date of lectures. B- The date when the oldest of his shaykhs died, it turns out that Abū Isḥāq, may Allah have mercy upon him, began his search for knowledge in the last quarter of the fourth century. It could also be before that, and Allah knows best.
His earnestness, perseverance, and spending his early life in seeking knowledge:
We knew from the foregoing that Ath-Thaʿlabiyy, may Allah have mercy upon him grew up in a an environment that valued knowledge to the point that the house in which he lived abounded in circles of knowledge and lessons of scholars.
This environment motivated in Ath-Thaʿlabiyy a great desire for knowledge, and diligence and persistence in the pursuing it.
Ath-Thaʿlabiyy was able to make a strong and successful investment of the atmosphere in which he lived. The one who contemplates the sermon of Imam Ath-Thaʿlabiyy, with which he initiated his Tafsir will fully realize the extent of Abū Isḥāq’ s strength in his academic achievement, and the degree of his perseverance and diligence.
What further indicates that resolution and high determination are the following:
A- His saying, may Allah have mercy upon him: “Since I left the cradle until I reached the age of adolescence I attended lectures of scholars of various ranks, and strove to have a share of this knowledge which is the foundation of religion, and pivot for sharia sciences. I spent days and nights with firm determination and hard effort, until Allah guided me to that with which I was able to know the truth from falsehood, what is good from what is best, what is sound from what is not, what is new from what is old, what is heresy and what is Sunnah, and what is a valid argument and what is a doubtful matter.” Such was the resolution of Abū Isḥāq, his perseverance and diligence in seeking knowledge, for he, may Allah have mercy upon him, used to join day with night and darkness with light, morning with evening with firm determination and hard effort.
What a resolution, and what diligence!
B- The big number of his shaykhs and the diversity of his resources:
Undoubtedly, this cannot be achieved except for those who are diligent and resolute in seeking knowledge. He frequented the gatherings of scholars and the lessons of knowledge and heard from this one, and read ove that one in continuous demand and ongoing effort, knowing no fatigue or boredom. 
And so was the attitude of Abū Isḥāq Ath-Thaʿlabiyy, until he achieved that great achievement represented in learning from three hundred shaykhs, and a large number of books and reports. 
This, without doubt, is a clear proof of the seriousness and diligence in seeking knowledge, and bending the knees in front of scholars.
C- The diversity of scientific material in his Tafsir:
He mentioned that he included in his book fourteen types of knowledge:
1-Prefaces and introductions. 2- Numbers of surahs and verses and stages of sending down the Qurʾān.
3-Stories and reasons of revelation. 4- Modes of recitation.
5-Defects and objections. 6- Arabic and different languages.
7-Parsing and analysis. 8- Commentary and interpretations.
9-Meanings and orientation. 10- Ambiguity and problems.
11-Rulings and jurisprudence. 12- Wisdom and anecdotes.
13-Virtues and extraordinary events. 14- News and relevant matters.
This is another evidence of the vastness of Ath-Thaʿlabi’s knowledge, may Allah have mercy upon him. This encyclopedic nature is nothing but the fruit of seriousness and high determination in seeking knowledge.
Where he acquired his knowledge
As Ath-Thaʿlabiyy’s areas of knowledge diversified, the places where Abū Isḥāq received this knowledge were various as well:
The house of Ath-Thaʿlabiyy: He, may Allah have mercy upon him, mentioned in the introduction of his book that he narrated Tafsir Ad-Dumyāṭiyy on the authority of his shaykh Abū Ḥāmid Aṣ-Ṣufiyy at his own house. He, may Allah have mercy upon him, said: Tafsir Ad-Dumyāṭiyy… Abū Ḥāmid Ahmad ibn Al-Walīd Aṣ-Ṣufiyy informed us via my recitation on him at my house in 408 AH. He also narrated on the authority of his shaykh Ibn Fanjuwayh at his own house as he said in his commentary of surat Al-Ikhlāṣ: “I was informed by Abu ʿAbdullah Al-Ḥusayn ibn Muḥammad ibn Al-Ḥusayn Ath-Thaqafiyy Al-Ḥāfiẓ through my recitation over him at my house.
The houses of his shaykhs: Ath-Thaʿlabiyy used to go to his shaykhs at their houses, sit with them in order to listen to them and read upon them. He used to visit the house of his shaykh from whom he narrated plentiful reports, Abu Muhammad ʿAbdullah ibn Ḥāmid Al-Asfahāniyy Al-Wazzān in order to sit in front of him and hear from him the Tafsir of Abu Ḥudhayfah An-Nahdiyy, which Ibn Ḥāmid narrated through his own chain of narrators back to Abu Ḥudhayfah. He, may Allah have mercy upon him, said: “Tafsir An-Nahdiyy, Abu Muhammad ʿAbdullah ibn Ḥāmid Al-Wazzān informed us through my reading over him at his house…etc.”
Mosques: 
Despite the large number of schools in Naysābūr, and scholars and students of knowledge’s interest in them, this, however did not affect the scientific status of the mosques which were considered the first scientific starting point in the Islamic world at the time.
Ath-Thaʿlabiyy, Abū Isḥāq was one of the oft-visitors of those mosques, as we find him stating in his Tafsir that he received one of his narrations in the mosque in Naysābūr. He says: “Abū ʿAliyy Al-Ḥusayn ibn Muḥammad ibn ʿAliyy ibn Ibrāhīm
 As-Sarrāj informed us through my reading upon him in the mosque, on Friday, in the year 388.”
Schools: When explaining the common state of the era of Ath-Thaʿlabi, we mentioned that Naysābūr, the city of Imam Ath-Thaʿlabi, was the starting point of the scientific schools in the Islamic world. Naysābūr was flourishing with these schools and had pride of them.
Among these schools were some of that were established by some of the shaykhs of Ath-Thaʿlabiyy, such as the school of his shaykh Abū Bakr Muḥammad bin Fūrak and the school of his shaykh Abū Isḥāq Al-Isfirāyīni.
E- His travels in pursuit of knowledge: Historians did not tell us anything about the travels of Imam Ath-Thaʿlabiyy, may Allah have mercy upon him, who was serious, diligent, and persistent in seeking knowledge, and who received knowledge from nearly three hundred shaykhs. Therefore, it is unlikely that he did not travel to the scholars wherever they were. But we cannot be certain that he, may Allah have mercy upon him, travelled due to several reasons:
First: Most of his shaykhs were from Naysābūr, or from those who came to settle in it.
Second: Those who wrote his biography made no mention of his travels.
Third: The absence of his huge books which amount to more than five hundred parts  makes this matter unknown to us.
Fourth: Reality does not preclude that he did not travel because Khurasan, and especially Naysābūr was a gathering place for knowledge and scholars to the point that it was the destination of seekers of knowledge at that time.
Fifth: I did not find, according to my research in his Tafsir, what indicates that he travelled, but what I found is that Abū Isḥāq left Naysābūr, but this journey did not go beyond the region of Khurasan.
He, may Allah have mercy on him, departed to Aṭ-Ṭābarān which is one of the villages of Ṭūs in Khorasan, located ten leagues away from Naysābūr. He heard in it from his shaykh, Abū Al- Ḥasan ʿAbd Ar-Raḥmān ibn Ibrāhīm ibn Muḥammad Aṭ-Ṭābarāniyy. He also travelled to Darb Al-Ḥājib, where he heard from his shaykh Yaʿqūb Al-ʿArūḍiyy.