Al-Kāfi

Hadith 1012
worship
8ـ عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ أَبِيهِ عَنِ ابْنِ أَبِي عُمَيْرٍ عَنْ حَمَّادٍ عَنِ الْحَلَبِيِّ عَنْ أَبِي عَبْدِ الله (عَلَيْهِ الْسَّلام) قَالَ الصَّلاَةُ ثَلاَثَةُ أَثْلاَثٍ ثُلُثٌ طَهُورٌ وَثُلُثٌ رُكُوعٌ وَثُلُثٌ سُجُودٌ.
8. Ali ibn Ibrahim has narrated from his father from Ibn Abi ‘Umayr from Hammad from al-Halabiy who has said the following: “Abu ‘Abd Allah (a.s.), has said, ‘Acts of Salah (prayer) fall in three categories; They are Tahur (cleansing), Ruku‘ (bowing down on one’s knees), and Sujud (prostration).”’
Source: Shaykh Muḥammad b. Yaʿqūb al-Kulaynī