Why Doesn't Surat At-Tawbah Begin With "Bismillah"

Question :

Unlike other chapters, why does Surat At-Tawbah begin without "Bismillahi-ar-Rahman-ir-Rahim (In the Name of Allâh, the Most Beneficent, the Most Merciful)"? Also,vbefore reading this chapter, we say, "I seek refuge in Allah from the Fire, from the evil of the disbelievers, and from the anger of the Almighty; and glory is for Allah and His Messenger." Is this invocation correct?

Answer:

The invocation that you mentioned for the beginning of Surah Bara'h (At-Tawbah) is an innovated supplication which there is no basis for, and it is not allowed for one to begin the Surah with it. When I was young, I used to see this invocation written as a footnote in some copies of the Qur'an. Whoever sees this in a copy of the Qur'an should blot it out, because it is an innovation and it is not related from the Prophet ﷺ .

As for your first question, we do not begin this chapter with "Bismillah" simply because it is not there; were it a part of the chapter, it would have been written in the Qur'an, for Allah Almighty says:
"Verily We: It is We Who have sent down the Thikr (i.e., the Qur'an) and surely, We will guard it (from corruption).

This is how it has reached us from the Prophet ﷺ The Companions, however, disagreed among themselves as has been related from 'Uthman as to whether it is a separate chapter or whether it is the completion of Surat Al-Anfal. So they separated between them without the "Bismillah". So this is a judgement on their part between two choices. For if it was certain that it was the remainder of Surat Al-Anfal then they would not have put a separation nor the "Bismillah," and if it were certain that it was a separate chapter then they would have put a separation and the "Bismillah." Since neither this nor that is confirmed, they put a separation there. This was a case of Ijtihad that agrees with what is correct, for it can be known with certainty that if the "Bismillah" were revealed before this chapter then they would have left it, without a doubt. This is because Allah Almighty says:
"Verily We: It is We Who have sent down the Thikr (i.e., the Qur'an) and surely, We will guard it (from corruption).
Therefore it is not legislated that one should begin the recitation of Surah Al-Bara'h with "Bismillah-ir-Rahman-ir-Rahim."

Source:
Ibn 'Uthaimin
Fatawa Islamiyah, Vol. 7 Pages 32-33