The ruling on one who forgets to recite al-Fatihah in a rak'ah

Question:
Honorable Shaykh (may Allah preserve him), a man prayed the Zuhr prayer, and when he prayed the third rak'ah, he did not recite Surat al-Fatihah. When the prayer ended, he remembered that he had not recited al-Fatihah. Does he have to repeat the prayer or not? May Allah reward you with good.

Answer:
A person should not pay attention to doubt or the whispers of Satan, for Satan may confuse him and say to him, "Did you not recite al-Fatihah?" Some people may recite al-Fatihah three or four times, and all of this is among the intrusive thoughts that are not acceptable. Rather, the Muslim should strive to have his heart present during the recitation and not pay attention to Satan when he says, "You did not recite, you did not recite." However, if he becomes certain, as this questioner said, if he becomes certain that he did not recite al-Fatihah, and then he reaches the tashahhud or something similar, he stands up and performs the rak'ah in which he did not recite al-Fatihah. He completes it. But if he does not remember it until after that, and he becomes certain, as he says, that he did not recite al-Fatihah, they repeat the entire prayer, because the imam's prayer is the prayer of the imam behind him.