It has also been reported from the Prophet, may Allah bless him and grant him peace, through several chains of transmission, in the hadiths of Abū Rāfiʿ, Abū Thaʿlaba, and others, that he said:

“Let me not find any of you reclining on his couch when word reaches him of something I have commanded or forbidden, saying, ‘The Quran is the arbiter between us and you: whatever we find in it to be lawful, we deem lawful, and whatever we find in it to be forbidden, we deem forbidden.’ Indeed, I have been given the Book and its like along with it.” In another narration: “Indeed, it is like the Book.”

The Quran was distinct in itself because Allah endowed it with inimitability, setting it apart from human speech. As He, the Most High, said:

“Say, ‘If mankind and the jinn gathered together to produce the like of this Quran, they could not produce its like, even if they helped one another.’”

Since it was also conveyed through mass transmission, no one aspired to change any of its words or letters. Satan, however, aspired to introduce distortion and alteration into its meanings through changes and reinterpretation, and to introduce omissions and additions into the hadiths by which he could mislead some of Allah’s servants. Allah, the Most High, therefore raised up expert critics, men of guidance and sound judgment. They repelled Satan’s party, distinguished truth from falsehood, and devoted themselves to safeguarding the Sunnah and the meanings of the Quran against additions and omissions.

Each scholar of religion, drawing upon what Allah had graciously bestowed upon him and the Muslims, fulfilled the role of those endowed with deep understanding—those who grasped the meanings of the Quran and hadith—by countering the errors that had arisen in these matters in earlier and later times. Some of these matters were manifest and clear, permitting no departure from them; others were subtle, allowing upright scholars to exercise independent scholarly judgment.

The scholars of transmission and the critics undertook the study of narrations and their chains of transmission. For this they travelled to distant lands, forsook the pleasure of sleep, parted from their wealth and children, spent both their newly acquired and inherited wealth, endured hardships patiently, and contented themselves with no more of this world than a traveller’s provisions,