The ruling on reciting a surah that does not shorten the prayer in the last two rak'ahs

Question : In the first two rak'ahs, he recited al-Fatihah, and in the last two rak'ahs, he added a surah that does not shorten the prayer.

Answer : I hold that if he intended to oppose the Sunnah, that is dangerous for his religion, not just for the prayer, because this is hostility toward Allah and His Messenger and opposition to them. However, if, for example, he said, "The matter is broad, and the Messenger (peace and blessings be upon him) recited in the last two rak'ahs according to the hadith of Abu Sa'id, and did not make it obligatory to recite anything extra besides al-Fatihah, and I intended to clarify that this is permissible," then that is less severe. And what is your name? Do you not want this upon yourselves, O Ibrahim? This is something that one who asks should strike his face for. No, no, it is a mistake, a clear opposition to the Sunnah. Yes.