What is the reason for the discrepancy between the fatwa prohibiting the saying, "I repent to Allah and the Messenger," and the Hadith in Muslim where Aisha said, "I repent to Allah and to His Messenger"?

The aforementioned fatwa is correct and does not contradict the Hadith, because the legal (Shar'i) repentance is an act of worship that can only be directed to Allah alone, as stated in His Almighty saying: (And turn to Allah in repentance, all of you, O believers, that you might succeed). As for Aisha's (may Allah be pleased with her) statement in the Hadith: "I repent to Allah and to His Messenger," repentance to the Messenger is to be understood in its linguistic sense, which is to turn back from error—meaning, to turn back from what one has erred in regarding the rights of Allah and the rights of His Messenger. It does not signify the legal (Shar'i) repentance. This is what Ibn 'Uthaymeen, Al-Tibi, and Al-Qari indicated. This is further supported by the repetition of the preposition "ila" (to) to denote the independence of turning back for each of them. This repentance to the Messenger is valid only during his lifetime. After his death, it is not permissible to say "I repent to the Messenger of Allah"; rather, one should say "I repent to Allah."