Praise be to Allah, and may peace and blessings be upon the Messenger of Allah.
A Muslim must believe in all the Books that Allah تعالى revealed to His Messengers. However, it is not correct to state with certainty that their number was one hundred and four, because the hadith specifying this number has not been established with an isnad that is sound enough to rely upon.
Belief in the Books that Allah تعالى revealed is one of the foundations of faith. Therefore, the Muslim believes in everything that Allah revealed to His Messengers, whether he knows the names and details of those Books or not.
Allah تعالى says:
“And say: ‘I believe in whatever Book Allah has revealed.’”
[Ash-Shura 42:15]
And He سبحانه says:
“Mankind were one community, then Allah sent the prophets as bearers of good news and warners, and He sent down with them the Book in truth to judge between people concerning that over which they differed.”
[Al-Baqarah 2:213]
And Allah تعالى says:
“Indeed, We sent Our Messengers with clear proofs, and We sent down with them the Book and the balance so that people may uphold justice.”
[Al-Hadid 57:25]
And He سبحانه says:
“Say: ‘We believe in Allah and what has been revealed to us and what was revealed to Abraham, Ishmael, Isaac, Jacob, and the Tribes, and what was given to Moses and Jesus, and what was given to the prophets from their Lord. We make no distinction between any of them, and to Him we submit.’”
[Al-Baqarah 2:136]
And Allah تعالى says:
“Say: ‘We believe in Allah and what has been revealed to us and what was revealed to Abraham, Ishmael, Isaac, Jacob, and the Tribes, and what was given to Moses, Jesus, and the prophets from their Lord. We make no distinction between any of them, and to Him we submit.’”
[Al ‘Imran 3:84]
Ibn Kathir رحمه الله said, explaining this:
“Allah تعالى guided His believing servants to believe in what was revealed to them through His Messenger Muhammad ﷺ in detail, and in what was revealed to the earlier prophets in general. He explicitly mentioned some of the Messengers and mentioned the rest of the prophets in general terms, and commanded them not to differentiate between any of them, but rather to believe in all of them.”
Accordingly, the Muslim believes in general in the Books that Allah تعالى revealed whose details have not been specified in revelation, without asserting a particular number for them. He believes in detail in those Books that Allah تعالى named, such as the Torah, the Gospel, the Psalms, and the Criterion, according to what is established in the revealed texts.
Muhammad ibn Nasr al-Marwazi رحمه الله said, explaining belief in the Books:
“And you believe that Allah has other Books besides these, which He revealed to His prophets, whose names and number are known only to the One who revealed them.”
It was narrated from Abu Dharr رضي الله عنه that he asked the Prophet ﷺ about the number of Books that Allah revealed. The hadith states:
“One hundred and four Books: fifty scriptures were revealed to Seth, thirty scriptures were revealed to Enoch, ten scriptures were revealed to Abraham, ten scriptures were revealed to Moses before the Torah, and the Torah, the Gospel, the Psalms, and the Criterion were revealed...”
Ibn Hibban narrated it in his Sahih.
However, this hadith is not established in terms of its chain of transmission. There has been criticism concerning one of its narrators, Ibrahim ibn Hisham al-Ghassani. A number of leading scholars of hadith criticism, including Abu Hatim and Abu Zur‘ah, criticized him and judged him to be severely weak.
Al-Dhahabi رحمه الله also discussed him, transmitting the statements of scholars concerning him in a manner indicating that his narration cannot be relied upon.
Ibn Kathir رحمه الله said:
“There is no doubt that more than one of the leading scholars of hadith criticism spoke against him because of this hadith.”
The hadith was also narrated through other chains, but these too contain defects in their isnads. Some contain weak or unknown narrators, and hadith scholars rejected some of these chains.
Ibn Rajab رحمه الله said:
“It has been narrated through several routes from Abu Dharr, and all of them contain grounds for criticism.”
Based on the above, it is not correct to assert that the number of Books Allah تعالى revealed was one hundred and four, because the evidence specifying this number has not been established through a reliable chain of transmission.
The obligation is to believe in the Books of Allah تعالى that have been authentically established, and to believe in general in everything Allah تعالى revealed to His prophets and Messengers, while withholding judgment concerning matters for which no authentic text has been established.
Therefore, it is not correct to attribute the numbers mentioned in circulating messages to the Prophet ﷺ with certainty, nor to say that this is the established number of the heavenly Books on the basis of this hadith.
It is obligatory to believe in all the Books that Allah تعالى revealed to His Messengers. We believe in detail in those that Allah تعالى named, and we believe in general in those whose names and details we do not know. As for specifying their number as one hundred and four, and specifying the number of scriptures revealed to Seth, Enoch, Abraham, and Moses, this cannot be stated with certainty, because the hadith of Abu Dharr concerning this matter has not been established through a chain of transmission suitable for reliance.
And Allah knows best.