The hadith known as the "hadith of Gabriel" is one of the most comprehensive hadith of the Prophet (peace be upon him). It touches upon almost every deed of Islam. Qaadhi Iyadh has pointed out that this hadith covers all of the aspects of internal and outward acts of worship. It touches upon the deeds that are related to the external organs as well as that of the heart. Indeed, he stated, "[It covers the religion] to such an extent that all religious sciences are found in it and branch out from it."

This hadith is known is also called "Umm al-Sunnah" (or "the foundation of the Sunnah") in the same way that Surah al-Faatiha is called "Umm al-Kitaab" (or "the Foundation of the Book"). In the same way that Surah al-Faatiha encompasses the meaning of the Qur'an as a whole, this hadith encompasses the meaning of the Sunnah as a whole.

This commentary of this hadith, extracted from the author's "Commentary on the Forty Hadith al-Nawawi," is one of many such commentaries throughout the history of Islam. It is, though, the first such commentary available in the English language