The Prophet ﷺ said, "You will never return to Allah with anything more excellent than what came from Him," meaning the Quran.
حدثنا بذلك إسحق بن منصور حدثنا عبد الرحمن بن مهدي عن معاوية عن العلاء بن الحارث عن زيد بن أرطاة
قال النبي ﷺ إنكم لن ترجعوا إلى الله بأفضل مما خرج منه يعني القرآن
No references are available.
Its chain of transmission is daif due to being mursal. Abu Dawud reported it in al-Marasil, no. 538, from the hadith of Ibn Mahdi, transmitting it this way. Hakim connected it, 1/555, as did Bayhaqi in al-Asma wa-Sifat, p. 236, but this is a mistake, and despite that Hakim graded it sahih and Dhahabi agreed with him. Muawiya here is Ibn Salih. The hadith has a corroborating witness that is daif and shadhdh found in Hakim, 2/441, where he graded it sahih and Dhahabi agreed with him, but in it is the scribe of Layth, who is daif, and the narrator transmitting from him is also daif.