Quietly, and it is not part of al-Fātiḥah …
His statement, “quietly,” means that he recites the basmalah quietly—that is, when the prayer is one in which the recitation is audible. As for a silent prayer, he will recite both the basmalah and the Qur’anic recitation quietly. Thus, his statement, “quietly,” means that those praying behind him do not hear it, even though he recites the rest aloud. This is because most of the hadiths reported from the Prophet ﷺ indicate that he recited it quietly (1). Indeed, it has been said that every hadith mentioning audible recitation of the basmalah is weak (2).
His statement, “and it is not part of al-Fātiḥah”: the pronoun refers to the basmalah. Rather, it is an independent verse with which every surah of the Quran begins, apart from Barāʾah, which does not contain the basmalah, based on the Companions’ independent judgment. Yet this judgment was undoubtedly founded upon revealed instruction, for we know that, had the basmalah been revealed between al-Anfāl and Barāʾah, it would necessarily have remained, since Allah says:
“Indeed, it is We who sent down the Reminder, and indeed, We will surely preserve it.” [al-Ḥijr: 9]
Since it was not there, it is known that the Companions’ judgment conformed to the reality of the matter.
The evidence that it is not part of al-Fātiḥah is the authentic report in al-Ṣaḥīḥ from Abu Hurayrah, may Allah be pleased with him, that the Prophet ﷺ said: “Allah, Most High, says: ‘I have divided the prayer between Me and My servant into two halves, and My servant shall have what he asks for. When the servant says, “All praise is for Allah, Lord of all worlds,” Allah, Most High, says: “My servant has praised Me” …’” (3)
The hadith.