Al-Kāfi
Hadith 640وَرُوِيَ أَنَّ أَمِيرَ الْمُؤْمِنِينَ (عَلَيْهِ السَّلاَم) كَانَ يُصَلِّي فِيهَا رَكْعَتَيْنِ يَقْرَأُ فِي الأُولَى الْحَمْدَ وَقُلْ هُوَ الله أَحَدٌ أَلْفَ مَرَّةٍ وَفِي الثَّانِيَةِ الْحَمْدَ وَقُلْ هُوَ الله أَحَدٌ مَرَّةً وَاحِدَةً.
4. It is narrated that ’Amir al-Mu’minin, would perform two Rak‘at salat (prayer). In the first Rak‘at, he would read Chapter 1 and (then) 112 of the Holy Quran one thousand times. In the second Rak‘at, he would read Chapter 1 and 112 once only.