I have memorized the pairings that the Messenger of Allah ﷺ used to recite together, eighteen surahs from the Mufassal and two surahs from the Ha-Mim chapters.
حدثنا عبد الصمد حدثنا مهدي حدثنا واصل عن أبي وائل
إني لأحفظ القرائن التي كان يقرن بينهن رسول الله ﷺ ثماني عشرة سورة من المفصل وسورتين من آل حم
Its chain of transmission is sahih. Mahdi is Ibn Maymun. Wasil is Ibn Hayan al-Ahdab al-Asadi, the seller of Sabiri cloth, and he is trustworthy. Ibn Main, Abu Dawud, Nasai, and others affirmed his trustworthiness, and the authors of the six books cited him. Bukhari gave his biography in al-Kabir 17/2/4. See also 3607, 3910, 3958, 3968, 4410.