Lexical Notes on the ḥadith
• “bi-Umm al-Qurʾān” – The verb “to recite” is in itself transitive, yet the preposition bi- is added here to stress that one must not begin the recitation except with the Mother of the Qurʾān.

• “La ṣalāh” – The particle lā has various functions; in this instance it is the genus-negating lā (lā al-nāfiyah li-l-jins).
Ibn Daqīq al-ʿĪd explains: When a negation occurs in the Prophet’s wording with a verb, the primary sense should be the negation of the act as recognised by the Law. Thus “no prayer” means “no legally valid prayer.” If, instead, we understood it as a denial of the physical act—which is obviously not absent—we would have to assume an implicit qualifier. Some scholars therefore supply “valid,” others “complete.”

• Umm al-Qurʾān – Al-Bukhārī said: It was called “Umm al-Kitāb” (Mother of the Book) because it is the first chapter to be written in the muṣḥaf and the first to be recited in prayer. Al-Qurṭubī added that it encapsulates every branch of Qurʾānic knowledge.

• Fātiḥat al-Kitāb – Al-Qurṭubī said: It is so named because the recitation of the Qurʾān is opened with it orally, the writing of the muṣḥaf begins with it on the page, and the prayers are opened with it.

Points Derived from the ḥadith
1 – Umm al-Qurʾān and Fātiḥat al-Kitāb are two of the names of the sūrah that begins, “All praise belongs to Allah, Lord of the worlds.” It is the Mother of the Qurʾān because the meanings of the entire Qurʾān return to what it contains; and it is the Opening of the Book because the Qurʾān is opened with it and the Companions began the master codex with it.
It possesses several other names, all of which testify to its merit and importance. In Ṣaḥīḥ al-Bukhārī (4474) the Prophet ﷺ said: “The greatest sūrah in the Qurʾān is ‘All praise belongs to Allah, Lord of the worlds’; it is the Seven Oft-Repeated.”