Abu Wa'il said: A man came to Sayyiduna Abdullah (may Allah be pleased with him) and said: Tonight I recited the whole of the Mufassal in one rak'ah. Sayyiduna Abdullah (may Allah be pleased with him) said: Rattling through it hastily like poetry (is that prayer)? I know the surahs of similar length and theme which the Messenger of Allah (peace and blessings be upon him) used to recite in one rak'ah. Then he mentioned twenty surahs from the beginning of the Mufassal, which were recited combined two by two.
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 9827