[1562/1] al-Kafi: Abu Ali al-Ash’ari from Muhammad b. Abd al-Jabbar from Safwan from Ishaq b. Ammar from Abi Basir from Abi Ja’far عليه السلام who said
The Qur’an came down as four fourths: A quarter concerning us, a quarter concerning our enemies, a quarter is Sunan (Precedents) and Amthāl (Similitudes), and a quarter is Farāʾiḍ (Obligations) and Aḥkām (Rulings)