Al-Kāfi - Volume 3 > Recitations in Salah (prayer)
Hadith #12

12ـ أَحْمَدُ بْنُ إِدْرِيسَ عَنْ مُحَمَّدِ بْنِ أَحْمَدَ عَنْ مُحَمَّدِ بْنِ عَبْدِ الْحَمِيدِ عَنْ سَيْفِ بْنِ عَمِيرَةَ عَنْ مَنْصُورِ بْنِ حَازِمٍ قَالَ قَالَ أَبُو عَبْدِ الله (عَلَيْهِ الْسَّلام) لاَ تَقْرَأْ فِي الْمَكْتُوبَةِ بِأَقَلَّ مِنْ سُورَةٍ وَلاَ بِأَكْثَرَ.

12. Ahmad ibn Idris has narrated from Muhammad ibn Ahmad from Muhammad ibn ‘Abd al-Hamid from Sayf ibn ‘Amirah from Mansur ibn Hazim who has said the following: “Abu ‘Abd Allah, ‘Alayhi al-Salam, has said, ‘You must not read less than a Surah (Chapter) in an obligatory Salah (prayer) or more.’”